Related
This question already has answers here:
How do I calculate the date six months from the current date using the datetime Python module?
(47 answers)
Closed 7 years ago.
I need to increment the month of a datetime value
next_month = datetime.datetime(mydate.year, mydate.month+1, 1)
when the month is 12, it becomes 13 and raises error "month must be in 1..12". (I expected the year would increment)
I wanted to use timedelta, but it doesn't take month argument.
There is relativedelta python package, but i don't want to install it just only for this.
Also there is a solution using strtotime.
time = strtotime(str(mydate));
next_month = date("Y-m-d", strtotime("+1 month", time));
I don't want to convert from datetime to str then to time, and then to datetime; therefore, it's still a library too
Does anyone have any good and simple solution just like using timedelta?
This is short and sweet method to add a month to a date using dateutil's relativedelta.
from datetime import datetime
from dateutil.relativedelta import relativedelta
date_after_month = datetime.today()+ relativedelta(months=1)
print('Today: ',datetime.today().strftime('%d/%m/%Y'))
print('After Month:', date_after_month.strftime('%d/%m/%Y'))
Today: 01/03/2013
After Month: 01/04/2013
A word of warning: relativedelta(months=1) and relativedelta(month=1) have different meanings. Passing month=1 will replace the month in original date to January whereas passing months=1 will add one month to original date.
Note: this will require python-dateutil module. If you are on Linux you need to run this command in the terminal in order to install it.
sudo apt-get update && sudo apt-get install python-dateutil
Explanation : Add month value in python
Edit - based on your comment of dates being needed to be rounded down if there are fewer days in the next month, here is a solution:
import datetime
import calendar
def add_months(sourcedate, months):
month = sourcedate.month - 1 + months
year = sourcedate.year + month // 12
month = month % 12 + 1
day = min(sourcedate.day, calendar.monthrange(year,month)[1])
return datetime.date(year, month, day)
In use:
>>> somedate = datetime.date.today()
>>> somedate
datetime.date(2010, 11, 9)
>>> add_months(somedate,1)
datetime.date(2010, 12, 9)
>>> add_months(somedate,23)
datetime.date(2012, 10, 9)
>>> otherdate = datetime.date(2010,10,31)
>>> add_months(otherdate,1)
datetime.date(2010, 11, 30)
Also, if you're not worried about hours, minutes and seconds you could use date rather than datetime. If you are worried about hours, minutes and seconds you need to modify my code to use datetime and copy hours, minutes and seconds from the source to the result.
Here's my salt :
current = datetime.datetime(mydate.year, mydate.month, 1)
next_month = datetime.datetime(mydate.year + int(mydate.month / 12), ((mydate.month % 12) + 1), 1)
Quick and easy :)
since no one suggested any solution, here is how i solved so far
year, month= divmod(mydate.month+1, 12)
if month == 0:
month = 12
year = year -1
next_month = datetime.datetime(mydate.year + year, month, 1)
Use the monthdelta package, it works just like timedelta but for calendar months rather than days/hours/etc.
Here's an example:
from monthdelta import MonthDelta
def prev_month(date):
"""Back one month and preserve day if possible"""
return date + MonthDelta(-1)
Compare that to the DIY approach:
def prev_month(date):
"""Back one month and preserve day if possible"""
day_of_month = date.day
if day_of_month != 1:
date = date.replace(day=1)
date -= datetime.timedelta(days=1)
while True:
try:
date = date.replace(day=day_of_month)
return date
except ValueError:
day_of_month -= 1
from datetime import timedelta
try:
next = (x.replace(day=1) + timedelta(days=31)).replace(day=x.day)
except ValueError: # January 31 will return last day of February.
next = (x + timedelta(days=31)).replace(day=1) - timedelta(days=1)
If you simply want the first day of the next month:
next = (x.replace(day=1) + timedelta(days=31)).replace(day=1)
To calculate the current, previous and next month:
import datetime
this_month = datetime.date.today().month
last_month = datetime.date.today().month - 1 or 12
next_month = (datetime.date.today().month + 1) % 12 or 12
Perhaps add the number of days in the current month using calendar.monthrange()?
import calendar, datetime
def increment_month(when):
days = calendar.monthrange(when.year, when.month)[1]
return when + datetime.timedelta(days=days)
now = datetime.datetime.now()
print 'It is now %s' % now
print 'In a month, it will be %s' % increment_month(now)
What about this one? (doesn't require any extra libraries)
from datetime import date, timedelta
from calendar import monthrange
today = date.today()
month_later = date(today.year, today.month, monthrange(today.year, today.month)[1]) + timedelta(1)
Simplest solution is to go at the end of the month (we always know that months have at least 28 days) and add enough days to move to the next moth:
>>> from datetime import datetime, timedelta
>>> today = datetime.today()
>>> today
datetime.datetime(2014, 4, 30, 11, 47, 27, 811253)
>>> (today.replace(day=28) + timedelta(days=10)).replace(day=today.day)
datetime.datetime(2014, 5, 30, 11, 47, 27, 811253)
Also works between years:
>>> dec31
datetime.datetime(2015, 12, 31, 11, 47, 27, 811253)
>>> today = dec31
>>> (today.replace(day=28) + timedelta(days=10)).replace(day=today.day)
datetime.datetime(2016, 1, 31, 11, 47, 27, 811253)
Just keep in mind that it is not guaranteed that the next month will have the same day, for example when moving from 31 Jan to 31 Feb it will fail:
>>> today
datetime.datetime(2016, 1, 31, 11, 47, 27, 811253)
>>> (today.replace(day=28) + timedelta(days=10)).replace(day=today.day)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: day is out of range for month
So this is a valid solution if you need to move to the first day of the next month, as you always know that the next month has day 1 (.replace(day=1)). Otherwise, to move to the last available day, you might want to use:
>>> today
datetime.datetime(2016, 1, 31, 11, 47, 27, 811253)
>>> next_month = (today.replace(day=28) + timedelta(days=10))
>>> import calendar
>>> next_month.replace(day=min(today.day,
calendar.monthrange(next_month.year, next_month.month)[1]))
datetime.datetime(2016, 2, 29, 11, 47, 27, 811253)
Similar in ideal to Dave Webb's solution, but without all of that tricky modulo arithmetic:
import datetime, calendar
def increment_month(date):
# Go to first of this month, and add 32 days to get to the next month
next_month = date.replace(day=1) + datetime.timedelta(32)
# Get the day of month that corresponds
day = min(date.day, calendar.monthrange(next_month.year, next_month.month)[1])
return next_month.replace(day=day)
This implementation might have some value for someone who is working with billing.
If you are working with billing, you probably want to get "the same date next month (if possible)" as opposed to "add 1/12 of one year".
What is so confusing about this is you actually need take into account two values if you are doing this continuously. Otherwise for any dates past the 27th, you'll keep losing a few days until you end up at the 27th after leap year.
The values you need to account for:
The value you want to add a month to
The day you started with
This way if you get bumped from the 31st down to the 30th when you add one month, you'll get bumped back up to the 31st for the next month that has that day.
This is how I did it:
def closest_date_next_month(year, month, day):
month = month + 1
if month == 13:
month = 1
year = year + 1
condition = True
while condition:
try:
return datetime.datetime(year, month, day)
except ValueError:
day = day-1
condition = day > 26
raise Exception('Problem getting date next month')
paid_until = closest_date_next_month(
last_paid_until.year,
last_paid_until.month,
original_purchase_date.day) # The trick is here, I'm using the original date, that I started adding from, not the last one
Well with some tweaks and use of timedelta here we go:
from datetime import datetime, timedelta
def inc_date(origin_date):
day = origin_date.day
month = origin_date.month
year = origin_date.year
if origin_date.month == 12:
delta = datetime(year + 1, 1, day) - origin_date
else:
delta = datetime(year, month + 1, day) - origin_date
return origin_date + delta
final_date = inc_date(datetime.today())
print final_date.date()
I was looking to solve the related problem of finding the date for the first of the following month, regardless of the day in the given date. This does not find the same day 1 month later.
So, if all you want is to put in December 12, 2014 (or any day in December) and get back January 1, 2015, try this:
import datetime
def get_next_month(date):
month = (date.month % 12) + 1
year = date.year + (date.month + 1 > 12)
return datetime.datetime(year, month, 1)
A solution without the use of calendar:
def add_month_year(date, years=0, months=0):
year, month = date.year + years, date.month + months + 1
dyear, month = divmod(month - 1, 12)
rdate = datetime.date(year + dyear, month + 1, 1) - datetime.timedelta(1)
return rdate.replace(day = min(rdate.day, date.day))
def add_month(d,n=1): return type(d)(d.year+(d.month+n-1)/12, (d.month+n-1)%12+1, 1)
Just Use This:
import datetime
today = datetime.datetime.today()
nextMonthDatetime = today + datetime.timedelta(days=(today.max.day - today.day)+1)
This is what I came up with
from calendar import monthrange
def same_day_months_after(start_date, months=1):
target_year = start_date.year + ((start_date.month + months) / 12)
target_month = (start_date.month + months) % 12
num_days_target_month = monthrange(target_year, target_month)[1]
return start_date.replace(year=target_year, month=target_month,
day=min(start_date.day, num_days_target_month))
def month_sub(year, month, sub_month):
result_month = 0
result_year = 0
if month > (sub_month % 12):
result_month = month - (sub_month % 12)
result_year = year - (sub_month / 12)
else:
result_month = 12 - (sub_month % 12) + month
result_year = year - (sub_month / 12 + 1)
return (result_year, result_month)
def month_add(year, month, add_month):
return month_sub(year, month, -add_month)
>>> month_add(2015, 7, 1)
(2015, 8)
>>> month_add(2015, 7, 20)
(2017, 3)
>>> month_add(2015, 7, 12)
(2016, 7)
>>> month_add(2015, 7, 24)
(2017, 7)
>>> month_add(2015, 7, -2)
(2015, 5)
>>> month_add(2015, 7, -12)
(2014, 7)
>>> month_add(2015, 7, -13)
(2014, 6)
example using the time object:
start_time = time.gmtime(time.time()) # start now
#increment one month
start_time = time.gmtime(time.mktime([start_time.tm_year, start_time.tm_mon+1, start_time.tm_mday, start_time.tm_hour, start_time.tm_min, start_time.tm_sec, 0, 0, 0]))
My very simple solution, which doesn't require any additional modules:
def addmonth(date):
if date.day < 20:
date2 = date+timedelta(32)
else :
date2 = date+timedelta(25)
date2.replace(date2.year, date2.month, day)
return date2
With python I want to calculate the delta days of a day_of_a_year day and its corresponding month, as well delta days for month + 1.
*Sorry I forgot to mention that the year is a known variable
eg.
def a(day_of_year):
<...>
return [(days_from_start_of_month),(days_untill_end_of_month)]
so
If
day_of_year = 32
a(32) = (2,28) #assuming the month which the day_of_year corresponds to starts from day 30 and ends to day 60.
So far im studying the datetime , timeutils and calendar modules and I really can't figure out the logic for the code! I wish i had something solid to show, but Im getting lost somewhere in timedelta functions.
The first day of the month is easy to construct, as is the first day of the next month. Once you have those, the rest is even easier. As pointed out by the OP, the calendar.monthrange function gives us the most readable method to get the last day of a month.
>>> from datetime import date, year
>>> import calendar
>>> def first_day(dt):
... # Simply copy year and month into new date instance
... return date(dt.year, dt.month, 1)
...
>>> def last_day(dt):
... days_in_month = calendar.monthrange(dt.year, dt.month)[1]
... return date(dt.year, dt.month, days_in_month)
...
>>> nth_day = 32
>>> day_of_year = date(2012, 1, 1) + timedelta(days=nth_day - 1)
>>> day_of_year
datetime.date(2012, 2, 1)
>>> first_day(day_of_year), last_day(day_of_year)
(datetime.date(2012, 2, 1), datetime.date(2012, 2, 29))
>>> day_of_year - first_day(day_of_year), last_day(day_of_year) - day_of_year
(datetime.timedelta(0), datetime.timedelta(28))
To combine these techniques into one function:
def delta_to_start_and_end(year, day_of_year):
dt = date(year, 1, 1) + timedelta(days=(day_of_year - 1))
def first_day(dt):
return date(dt.year, dt.month, 1)
def last_day(dt):
days_in_month = calendar.monthrange(dt.year, dt.month)[1]
return date(dt.year, dt.month, days_in_month)
return (dt - first_day(dt)).days, (last_day(dt) - dt).days
Output:
>>> delta_to_start_and_end(2012, 32)
(0, 28)
>>> delta_to_start_and_end(2011, 32)
(0, 27)
>>> delta_to_start_and_end(2012, 34)
(2, 26)
>>> delta_to_start_and_end(2012, 364)
(28, 2)
I'm not sure if you want to add 1 to each of these two values; currently the first day of the month (first example) gives you 0 as the first value and (days-in-the-month - 1) as the second value, as this is the difference in days from those points. It's trivial to add + 1 twice on the last line of the delta_to_start_and_end function if you need these.
As a historic note, a previous version of this answer used a different method to calculate the last day of a month without the calendar module:
def last_day(dt):
rest, month = divmod(dt.month, 12)
return date(dt.year + rest, month + 1, 1) - timedelta(days=1)
This function uses the divmod builtin function to handle the 'current month is December' edge-case; in that case the next month is not 13, but 1 and we'd need to increase the year by one as well. Rolling over a number back to the 'start' is the modulus of the number, but the divmod function gives us the divisor as well, which happens to be 1 if the current month is 12. This gives us a handy indicator when to increase the year.
I don't think that there's an existing library that works for this. You have to make something yourself, like this:
monthdays = (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31)
day = 32
total = 0
for i in monthdays:
if day - total - i < 0:
before = day - total
after = total + i - day
break
total += i
print before, after
(just a quick start, there is possibly a more elegant way)
I have the need to be able to accurately find the months between two dates in python. I have a solution that works but its not very good (as in elegant) or fast.
dateRange = [datetime.strptime(dateRanges[0], "%Y-%m-%d"), datetime.strptime(dateRanges[1], "%Y-%m-%d")]
months = []
tmpTime = dateRange[0]
oneWeek = timedelta(weeks=1)
tmpTime = tmpTime.replace(day=1)
dateRange[0] = tmpTime
dateRange[1] = dateRange[1].replace(day=1)
lastMonth = tmpTime.month
months.append(tmpTime)
while tmpTime < dateRange[1]:
if lastMonth != 12:
while tmpTime.month <= lastMonth:
tmpTime += oneWeek
tmpTime = tmpTime.replace(day=1)
months.append(tmpTime)
lastMonth = tmpTime.month
else:
while tmpTime.month >= lastMonth:
tmpTime += oneWeek
tmpTime = tmpTime.replace(day=1)
months.append(tmpTime)
lastMonth = tmpTime.month
So just to explain, what I'm doing here is taking the two dates and converting them from iso format into python datetime objects. Then I loop through adding a week to the start datetime object and check if the numerical value of the month is greater (unless the month is December then it checks if the date is less), If the value is greater I append it to the list of months and keep looping through until I get to my end date.
It works perfectly it just doesn't seem like a good way of doing it...
Start by defining some test cases, then you will see that the function is very simple and needs no loops
from datetime import datetime
def diff_month(d1, d2):
return (d1.year - d2.year) * 12 + d1.month - d2.month
assert diff_month(datetime(2010,10,1), datetime(2010,9,1)) == 1
assert diff_month(datetime(2010,10,1), datetime(2009,10,1)) == 12
assert diff_month(datetime(2010,10,1), datetime(2009,11,1)) == 11
assert diff_month(datetime(2010,10,1), datetime(2009,8,1)) == 14
You should add some test cases to your question, as there are lots of potential corner cases to cover - there is more than one way to define the number of months between two dates.
One liner to find a list of datetimes, incremented by month, between two dates.
import datetime
from dateutil.rrule import rrule, MONTHLY
strt_dt = datetime.date(2001,1,1)
end_dt = datetime.date(2005,6,1)
dates = [dt for dt in rrule(MONTHLY, dtstart=strt_dt, until=end_dt)]
This worked for me -
from datetime import datetime
from dateutil import relativedelta
date1 = datetime.strptime('2011-08-15 12:00:00', '%Y-%m-%d %H:%M:%S')
date2 = datetime.strptime('2012-02-15', '%Y-%m-%d')
r = relativedelta.relativedelta(date2, date1)
r.months + (12*r.years)
from dateutil import relativedelta
r = relativedelta.relativedelta(date1, date2)
months_difference = (r.years * 12) + r.months
You can easily calculate this using rrule from dateutil module:
from dateutil import rrule
from datetime import date
print(list(rrule.rrule(rrule.MONTHLY, dtstart=date(2013, 11, 1), until=date(2014, 2, 1))))
will give you:
[datetime.datetime(2013, 11, 1, 0, 0),
datetime.datetime(2013, 12, 1, 0, 0),
datetime.datetime(2014, 1, 1, 0, 0),
datetime.datetime(2014, 2, 1, 0, 0)]
Get the ending month (relative to the year and month of the start month ex: 2011 January = 13 if your start date starts on 2010 Oct) and then generate the datetimes beginning the start month and that end month like so:
dt1, dt2 = dateRange
start_month=dt1.month
end_months=(dt2.year-dt1.year)*12 + dt2.month+1
dates=[datetime.datetime(year=yr, month=mn, day=1) for (yr, mn) in (
((m - 1) / 12 + dt1.year, (m - 1) % 12 + 1) for m in range(start_month, end_months)
)]
if both dates are on the same year, it could also be simply written as:
dates=[datetime.datetime(year=dt1.year, month=mn, day=1) for mn in range(dt1.month, dt2.month + 1)]
My simple solution:
import datetime
def months(d1, d2):
return d1.month - d2.month + 12*(d1.year - d2.year)
d1 = datetime.datetime(2009, 9, 26)
d2 = datetime.datetime(2019, 9, 26)
print(months(d1, d2))
This post nails it! Use dateutil.relativedelta.
from datetime import datetime
from dateutil import relativedelta
date1 = datetime.strptime(str('2011-08-15 12:00:00'), '%Y-%m-%d %H:%M:%S')
date2 = datetime.strptime(str('2012-02-15'), '%Y-%m-%d')
r = relativedelta.relativedelta(date2, date1)
r.months
Update 2018-04-20: it seems that OP #Joshkunz was asking for finding which months are between two dates, instead of "how many months" are between two dates. So I am not sure why #JohnLaRooy is upvoted for more than 100 times. #Joshkunz indicated in the comment under the original question he wanted the actual dates [or the months], instead of finding the total number of months.
So it appeared the question wanted, for between two dates 2018-04-11 to 2018-06-01
Apr 2018, May 2018, June 2018
And what if it is between 2014-04-11 to 2018-06-01? Then the answer would be
Apr 2014, May 2014, ..., Dec 2014, Jan 2015, ..., Jan 2018, ..., June 2018
So that's why I had the following pseudo code many years ago. It merely suggested using the two months as end points and loop through them, incrementing by one month at a time. #Joshkunz mentioned he wanted the "months" and he also mentioned he wanted the "dates", without knowing exactly, it was difficult to write the exact code, but the idea is to use one simple loop to loop through the end points, and incrementing one month at a time.
The answer 8 years ago in 2010:
If adding by a week, then it will approximately do work 4.35 times the work as needed. Why not just:
1. get start date in array of integer, set it to i: [2008, 3, 12],
and change it to [2008, 3, 1]
2. get end date in array: [2010, 10, 26]
3. add the date to your result by parsing i
increment the month in i
if month is >= 13, then set it to 1, and increment the year by 1
until either the year in i is > year in end_date,
or (year in i == year in end_date and month in i > month in end_date)
just pseduo code for now, haven't tested, but i think the idea along the same line will work.
Define a "month" as 1/12 year, then do this:
def month_diff(d1, d2):
"""Return the number of months between d1 and d2,
such that d2 + month_diff(d1, d2) == d1
"""
diff = (12 * d1.year + d1.month) - (12 * d2.year + d2.month)
return diff
You might try to define a month as "a period of either 29, 28, 30 or 31 days (depending on the year)". But you you do that, you have an additional problem to solve.
While it's usually clear that June 15th + 1 month should be July 15th, it's not usually not clear if January 30th + 1 month is in February or March. In the latter case, you may be compelled to compute the date as February 30th, then "correct" it to March 2nd. But when you do that, you'll find that March 2nd - 1 month is clearly February 2nd. Ergo, reductio ad absurdum (this operation is not well defined).
Here's how to do this with Pandas FWIW:
import pandas as pd
pd.date_range("1990/04/03", "2014/12/31", freq="MS")
DatetimeIndex(['1990-05-01', '1990-06-01', '1990-07-01', '1990-08-01',
'1990-09-01', '1990-10-01', '1990-11-01', '1990-12-01',
'1991-01-01', '1991-02-01',
...
'2014-03-01', '2014-04-01', '2014-05-01', '2014-06-01',
'2014-07-01', '2014-08-01', '2014-09-01', '2014-10-01',
'2014-11-01', '2014-12-01'],
dtype='datetime64[ns]', length=296, freq='MS')
Notice it starts with the month after the given start date.
Many people have already given you good answers to solve this but I have not read any using list comprehension so I give you what I used for a similar use case :
def compute_months(first_date, second_date):
year1, month1, year2, month2 = map(
int,
(first_date[:4], first_date[5:7], second_date[:4], second_date[5:7])
)
return [
'{:0>4}-{:0>2}'.format(year, month)
for year in range(year1, year2 + 1)
for month in range(month1 if year == year1 else 1, month2 + 1 if year == year2 else 13)
]
>>> first_date = "2016-05"
>>> second_date = "2017-11"
>>> compute_months(first_date, second_date)
['2016-05',
'2016-06',
'2016-07',
'2016-08',
'2016-09',
'2016-10',
'2016-11',
'2016-12',
'2017-01',
'2017-02',
'2017-03',
'2017-04',
'2017-05',
'2017-06',
'2017-07',
'2017-08',
'2017-09',
'2017-10',
'2017-11']
There is a simple solution based on 360 day years, where all months have 30 days.
It fits most use cases where, given two dates, you need to calculate the number of full months plus the remaining days.
from datetime import datetime, timedelta
def months_between(start_date, end_date):
#Add 1 day to end date to solve different last days of month
s1, e1 = start_date , end_date + timedelta(days=1)
#Convert to 360 days
s360 = (s1.year * 12 + s1.month) * 30 + s1.day
e360 = (e1.year * 12 + e1.month) * 30 + e1.day
#Count days between the two 360 dates and return tuple (months, days)
return divmod(e360 - s360, 30)
print "Counting full and half months"
print months_between( datetime(2012, 01, 1), datetime(2012, 03, 31)) #3m
print months_between( datetime(2012, 01, 1), datetime(2012, 03, 15)) #2m 15d
print months_between( datetime(2012, 01, 16), datetime(2012, 03, 31)) #2m 15d
print months_between( datetime(2012, 01, 16), datetime(2012, 03, 15)) #2m
print "Adding +1d and -1d to 31 day month"
print months_between( datetime(2011, 12, 01), datetime(2011, 12, 31)) #1m 0d
print months_between( datetime(2011, 12, 02), datetime(2011, 12, 31)) #-1d => 29d
print months_between( datetime(2011, 12, 01), datetime(2011, 12, 30)) #30d => 1m
print "Adding +1d and -1d to 29 day month"
print months_between( datetime(2012, 02, 01), datetime(2012, 02, 29)) #1m 0d
print months_between( datetime(2012, 02, 02), datetime(2012, 02, 29)) #-1d => 29d
print months_between( datetime(2012, 02, 01), datetime(2012, 02, 28)) #28d
print "Every month has 30 days - 26/M to 5/M+1 always counts 10 days"
print months_between( datetime(2011, 02, 26), datetime(2011, 03, 05))
print months_between( datetime(2012, 02, 26), datetime(2012, 03, 05))
print months_between( datetime(2012, 03, 26), datetime(2012, 04, 05))
Somewhat a little prettified solution by #Vin-G.
import datetime
def monthrange(start, finish):
months = (finish.year - start.year) * 12 + finish.month + 1
for i in xrange(start.month, months):
year = (i - 1) / 12 + start.year
month = (i - 1) % 12 + 1
yield datetime.date(year, month, 1)
You can also use the arrow library. This is a simple example:
from datetime import datetime
import arrow
start = datetime(2014, 1, 17)
end = datetime(2014, 6, 20)
for d in arrow.Arrow.range('month', start, end):
print d.month, d.format('MMMM')
This will print:
1 January
2 February
3 March
4 April
5 May
6 June
Hope this helps!
Get difference in number of days, months and years between two dates.
import datetime
from dateutil.relativedelta import relativedelta
iphead_proc_dt = datetime.datetime.now()
new_date = iphead_proc_dt + relativedelta(months=+25, days=+23)
# Get Number of Days difference bewtween two dates
print((new_date - iphead_proc_dt).days)
difference = relativedelta(new_date, iphead_proc_dt)
# Get Number of Months difference bewtween two dates
print(difference.months + 12 * difference.years)
# Get Number of Years difference bewtween two dates
print(difference.years)
Try something like this. It presently includes the month if both dates happen to be in the same month.
from datetime import datetime,timedelta
def months_between(start,end):
months = []
cursor = start
while cursor <= end:
if cursor.month not in months:
months.append(cursor.month)
cursor += timedelta(weeks=1)
return months
Output looks like:
>>> start = datetime.now() - timedelta(days=120)
>>> end = datetime.now()
>>> months_between(start,end)
[6, 7, 8, 9, 10]
You could use python-dateutil. See Python: Difference of 2 datetimes in months
just like range function, when month is 13, go to next year
def year_month_range(start_date, end_date):
'''
start_date: datetime.date(2015, 9, 1) or datetime.datetime
end_date: datetime.date(2016, 3, 1) or datetime.datetime
return: datetime.date list of 201509, 201510, 201511, 201512, 201601, 201602
'''
start, end = start_date.strftime('%Y%m'), end_date.strftime('%Y%m')
assert len(start) == 6 and len(end) == 6
start, end = int(start), int(end)
year_month_list = []
while start < end:
year, month = divmod(start, 100)
if month == 13:
start += 88 # 201513 + 88 = 201601
continue
year_month_list.append(datetime.date(year, month, 1))
start += 1
return year_month_list
example in python shell
>>> import datetime
>>> s = datetime.date(2015,9,1)
>>> e = datetime.date(2016, 3, 1)
>>> year_month_set_range(s, e)
[datetime.date(2015, 11, 1), datetime.date(2015, 9, 1), datetime.date(2016, 1, 1), datetime.date(2016, 2, 1),
datetime.date(2015, 12, 1), datetime.date(2015, 10, 1)]
It can be done using datetime.timedelta, where the number of days for skipping to next month can be obtained by calender.monthrange. monthrange returns weekday (0-6 ~ Mon-Sun) and number of days (28-31) for a given year and month.
For example: monthrange(2017, 1) returns (6,31).
Here is the script using this logic to iterate between two months.
from datetime import timedelta
import datetime as dt
from calendar import monthrange
def month_iterator(start_month, end_month):
start_month = dt.datetime.strptime(start_month,
'%Y-%m-%d').date().replace(day=1)
end_month = dt.datetime.strptime(end_month,
'%Y-%m-%d').date().replace(day=1)
while start_month <= end_month:
yield start_month
start_month = start_month + timedelta(days=monthrange(start_month.year,
start_month.month)[1])
`
it seems that the answers are unsatisfactory and I have since use my own code which is easier to understand
from datetime import datetime
from dateutil import relativedelta
date1 = datetime.strptime(str('2017-01-01'), '%Y-%m-%d')
date2 = datetime.strptime(str('2019-03-19'), '%Y-%m-%d')
difference = relativedelta.relativedelta(date2, date1)
months = difference.months
years = difference.years
# add in the number of months (12) for difference in years
months += 12 * difference.years
months
from datetime import datetime
from dateutil import relativedelta
def get_months(d1, d2):
date1 = datetime.strptime(str(d1), '%Y-%m-%d')
date2 = datetime.strptime(str(d2), '%Y-%m-%d')
print (date2, date1)
r = relativedelta.relativedelta(date2, date1)
months = r.months + 12 * r.years
if r.days > 0:
months += 1
print (months)
return months
assert get_months('2018-08-13','2019-06-19') == 11
assert get_months('2018-01-01','2019-06-19') == 18
assert get_months('2018-07-20','2019-06-19') == 11
assert get_months('2018-07-18','2019-06-19') == 12
assert get_months('2019-03-01','2019-06-19') == 4
assert get_months('2019-03-20','2019-06-19') == 3
assert get_months('2019-01-01','2019-06-19') == 6
assert get_months('2018-09-09','2019-06-19') == 10
#This definition gives an array of months between two dates.
import datetime
def MonthsBetweenDates(BeginDate, EndDate):
firstyearmonths = [mn for mn in range(BeginDate.month, 13)]<p>
lastyearmonths = [mn for mn in range(1, EndDate.month+1)]<p>
months = [mn for mn in range(1, 13)]<p>
numberofyearsbetween = EndDate.year - BeginDate.year - 1<p>
return firstyearmonths + months * numberofyearsbetween + lastyearmonths<p>
#example
BD = datetime.datetime.strptime("2000-35", '%Y-%j')
ED = datetime.datetime.strptime("2004-200", '%Y-%j')
MonthsBetweenDates(BD, ED)
Usually 90 days are NOT 3 months literally, just a reference.
So, finally, you need to check if days are bigger than 15 to add +1 to month counter. or better, add another elif with half month counter.
From this other stackoverflow answer i've finally ended with that:
#/usr/bin/env python
# -*- coding: utf8 -*-
import datetime
from datetime import timedelta
from dateutil.relativedelta import relativedelta
import calendar
start_date = datetime.date.today()
end_date = start_date + timedelta(days=111)
start_month = calendar.month_abbr[int(start_date.strftime("%m"))]
print str(start_date) + " to " + str(end_date)
months = relativedelta(end_date, start_date).months
days = relativedelta(end_date, start_date).days
print months, "months", days, "days"
if days > 16:
months += 1
print "around " + str(months) + " months", "(",
for i in range(0, months):
print calendar.month_abbr[int(start_date.strftime("%m"))],
start_date = start_date + relativedelta(months=1)
print ")"
Output:
2016-02-29 2016-06-14
3 months 16 days
around 4 months ( Feb Mar Apr May )
I've noticed that doesn't work if you add more than days left in current year, and that's is unexpected.
Here is my solution for this:
def calc_age_months(from_date, to_date):
from_date = time.strptime(from_date, "%Y-%m-%d")
to_date = time.strptime(to_date, "%Y-%m-%d")
age_in_months = (to_date.tm_year - from_date.tm_year)*12 + (to_date.tm_mon - from_date.tm_mon)
if to_date.tm_mday < from_date.tm_mday:
return age_in_months -1
else
return age_in_months
This will handle some edge cases as well where the difference in months between 31st Dec 2018 and 1st Jan 2019 will be zero (since the difference is only a day).
Assuming upperDate is always later than lowerDate and both are datetime.date objects:
if lowerDate.year == upperDate.year:
monthsInBetween = range( lowerDate.month + 1, upperDate.month )
elif upperDate.year > lowerDate.year:
monthsInBetween = range( lowerDate.month + 1, 12 )
for year in range( lowerDate.year + 1, upperDate.year ):
monthsInBetween.extend( range(1,13) )
monthsInBetween.extend( range( 1, upperDate.month ) )
I haven't tested this thoroughly, but it looks like it should do the trick.
Here is a method:
def months_between(start_dt, stop_dt):
month_list = []
total_months = 12*(stop_dt.year-start_dt.year)+(stop_dt.month-start_d.month)+1
if total_months > 0:
month_list=[ datetime.date(start_dt.year+int((start_dt+i-1)/12),
((start_dt-1+i)%12)+1,
1) for i in xrange(0,total_months) ]
return month_list
This is first computing the total number of months between the two dates, inclusive. Then it creates a list using the first date as the base and performs modula arithmetic to create the date objects.
I actually needed to do something pretty similar just now
Ended up writing a function which returns a list of tuples indicating the start and end of each month between two sets of dates so I could write some SQL queries off the back of it for monthly totals of sales etc.
I'm sure it can be improved by someone who knows what they're doing but hope it helps...
The returned value look as follows (generating for today - 365days until today as an example)
[ (datetime.date(2013, 5, 1), datetime.date(2013, 5, 31)),
(datetime.date(2013, 6, 1), datetime.date(2013, 6, 30)),
(datetime.date(2013, 7, 1), datetime.date(2013, 7, 31)),
(datetime.date(2013, 8, 1), datetime.date(2013, 8, 31)),
(datetime.date(2013, 9, 1), datetime.date(2013, 9, 30)),
(datetime.date(2013, 10, 1), datetime.date(2013, 10, 31)),
(datetime.date(2013, 11, 1), datetime.date(2013, 11, 30)),
(datetime.date(2013, 12, 1), datetime.date(2013, 12, 31)),
(datetime.date(2014, 1, 1), datetime.date(2014, 1, 31)),
(datetime.date(2014, 2, 1), datetime.date(2014, 2, 28)),
(datetime.date(2014, 3, 1), datetime.date(2014, 3, 31)),
(datetime.date(2014, 4, 1), datetime.date(2014, 4, 30)),
(datetime.date(2014, 5, 1), datetime.date(2014, 5, 31))]
Code as follows (has some debug stuff which can be removed):
#! /usr/env/python
import datetime
def gen_month_ranges(start_date=None, end_date=None, debug=False):
today = datetime.date.today()
if not start_date: start_date = datetime.datetime.strptime(
"{0}/01/01".format(today.year),"%Y/%m/%d").date() # start of this year
if not end_date: end_date = today
if debug: print("Start: {0} | End {1}".format(start_date, end_date))
# sense-check
if end_date < start_date:
print("Error. Start Date of {0} is greater than End Date of {1}?!".format(start_date, end_date))
return None
date_ranges = [] # list of tuples (month_start, month_end)
current_year = start_date.year
current_month = start_date.month
while current_year <= end_date.year:
next_month = current_month + 1
next_year = current_year
if next_month > 12:
next_month = 1
next_year = current_year + 1
month_start = datetime.datetime.strptime(
"{0}/{1}/01".format(current_year,
current_month),"%Y/%m/%d").date() # start of month
month_end = datetime.datetime.strptime(
"{0}/{1}/01".format(next_year,
next_month),"%Y/%m/%d").date() # start of next month
month_end = month_end+datetime.timedelta(days=-1) # start of next month less one day
range_tuple = (month_start, month_end)
if debug: print("Month runs from {0} --> {1}".format(
range_tuple[0], range_tuple[1]))
date_ranges.append(range_tuple)
if current_month == 12:
current_month = 1
current_year += 1
if debug: print("End of year encountered, resetting months")
else:
current_month += 1
if debug: print("Next iteration for {0}-{1}".format(
current_year, current_month))
if current_year == end_date.year and current_month > end_date.month:
if debug: print("Final month encountered. Terminating loop")
break
return date_ranges
if __name__ == '__main__':
print("Running in standalone mode. Debug set to True")
from pprint import pprint
pprint(gen_month_ranges(debug=True), indent=4)
pprint(gen_month_ranges(start_date=datetime.date.today()+datetime.timedelta(days=-365),
debug=True), indent=4)
Assuming that you wanted to know the "fraction" of the month that dates were in, which I did, then you need to do a bit more work.
from datetime import datetime, date
import calendar
def monthdiff(start_period, end_period, decimal_places = 2):
if start_period > end_period:
raise Exception('Start is after end')
if start_period.year == end_period.year and start_period.month == end_period.month:
days_in_month = calendar.monthrange(start_period.year, start_period.month)[1]
days_to_charge = end_period.day - start_period.day+1
diff = round(float(days_to_charge)/float(days_in_month), decimal_places)
return diff
months = 0
# we have a start date within one month and not at the start, and an end date that is not
# in the same month as the start date
if start_period.day > 1:
last_day_in_start_month = calendar.monthrange(start_period.year, start_period.month)[1]
days_to_charge = last_day_in_start_month - start_period.day +1
months = months + round(float(days_to_charge)/float(last_day_in_start_month), decimal_places)
start_period = datetime(start_period.year, start_period.month+1, 1)
last_day_in_last_month = calendar.monthrange(end_period.year, end_period.month)[1]
if end_period.day != last_day_in_last_month:
# we have lest days in the last month
months = months + round(float(end_period.day) / float(last_day_in_last_month), decimal_places)
last_day_in_previous_month = calendar.monthrange(end_period.year, end_period.month - 1)[1]
end_period = datetime(end_period.year, end_period.month - 1, last_day_in_previous_month)
#whatever happens, we now have a period of whole months to calculate the difference between
if start_period != end_period:
months = months + (end_period.year - start_period.year) * 12 + (end_period.month - start_period.month) + 1
# just counter for any final decimal place manipulation
diff = round(months, decimal_places)
return diff
assert monthdiff(datetime(2015,1,1), datetime(2015,1,31)) == 1
assert monthdiff(datetime(2015,1,1), datetime(2015,02,01)) == 1.04
assert monthdiff(datetime(2014,1,1), datetime(2014,12,31)) == 12
assert monthdiff(datetime(2014,7,1), datetime(2015,06,30)) == 12
assert monthdiff(datetime(2015,1,10), datetime(2015,01,20)) == 0.35
assert monthdiff(datetime(2015,1,10), datetime(2015,02,20)) == 0.71 + 0.71
assert monthdiff(datetime(2015,1,31), datetime(2015,02,01)) == round(1.0/31.0,2) + round(1.0/28.0,2)
assert monthdiff(datetime(2013,1,31), datetime(2015,02,01)) == 12*2 + round(1.0/31.0,2) + round(1.0/28.0,2)
provides an example that works out the number of months between two dates inclusively, including the fraction of each month that the date is in. This means that you can work out how many months is between 2015-01-20 and 2015-02-14, where the fraction of the date in the month of January is determined by the number of days in January; or equally taking into account that the number of days in February can change form year to year.
For my reference, this code is also on github - https://gist.github.com/andrewyager/6b9284a4f1cdb1779b10
Try this:
dateRange = [datetime.strptime(dateRanges[0], "%Y-%m-%d"),
datetime.strptime(dateRanges[1], "%Y-%m-%d")]
delta_time = max(dateRange) - min(dateRange)
#Need to use min(dateRange).month to account for different length month
#Note that timedelta returns a number of days
delta_datetime = (datetime(1, min(dateRange).month, 1) + delta_time -
timedelta(days=1)) #min y/m/d are 1
months = ((delta_datetime.year - 1) * 12 + delta_datetime.month -
min(dateRange).month)
print months
Shouldn't matter what order you input the dates, and it takes into account the difference in month lengths.
I have a datetime object produced using strptime().
>>> tm
datetime.datetime(2010, 6, 10, 3, 56, 23)
What I need to do is round the minute to the closest 10th minute. What I have been doing up to this point was taking the minute value and using round() on it.
min = round(tm.minute, -1)
However, as with the above example, it gives an invalid time when the minute value is greater than 56. i.e.: 3:60
What is a better way to do this? Does datetime support this?
This will get the 'floor' of a datetime object stored in tm rounded to the 10 minute mark before tm.
tm = tm - datetime.timedelta(minutes=tm.minute % 10,
seconds=tm.second,
microseconds=tm.microsecond)
If you want classic rounding to the nearest 10 minute mark, do this:
discard = datetime.timedelta(minutes=tm.minute % 10,
seconds=tm.second,
microseconds=tm.microsecond)
tm -= discard
if discard >= datetime.timedelta(minutes=5):
tm += datetime.timedelta(minutes=10)
or this:
tm += datetime.timedelta(minutes=5)
tm -= datetime.timedelta(minutes=tm.minute % 10,
seconds=tm.second,
microseconds=tm.microsecond)
General function to round a datetime at any time lapse in seconds:
def roundTime(dt=None, roundTo=60):
"""Round a datetime object to any time lapse in seconds
dt : datetime.datetime object, default now.
roundTo : Closest number of seconds to round to, default 1 minute.
Author: Thierry Husson 2012 - Use it as you want but don't blame me.
"""
if dt == None : dt = datetime.datetime.now()
seconds = (dt.replace(tzinfo=None) - dt.min).seconds
rounding = (seconds+roundTo/2) // roundTo * roundTo
return dt + datetime.timedelta(0,rounding-seconds,-dt.microsecond)
Samples with 1 hour rounding & 30 minutes rounding:
print roundTime(datetime.datetime(2012,12,31,23,44,59,1234),roundTo=60*60)
2013-01-01 00:00:00
print roundTime(datetime.datetime(2012,12,31,23,44,59,1234),roundTo=30*60)
2012-12-31 23:30:00
I used Stijn Nevens code (thank you Stijn) and have a little add-on to share. Rounding up, down and rounding to nearest.
update 2019-03-09 = comment Spinxz incorporated; thank you.
update 2019-12-27 = comment Bart incorporated; thank you.
Tested for date_delta of "X hours" or "X minutes" or "X seconds".
import datetime
def round_time(dt=None, date_delta=datetime.timedelta(minutes=1), to='average'):
"""
Round a datetime object to a multiple of a timedelta
dt : datetime.datetime object, default now.
dateDelta : timedelta object, we round to a multiple of this, default 1 minute.
from: http://stackoverflow.com/questions/3463930/how-to-round-the-minute-of-a-datetime-object-python
"""
round_to = date_delta.total_seconds()
if dt is None:
dt = datetime.now()
seconds = (dt - dt.min).seconds
if seconds % round_to == 0 and dt.microsecond == 0:
rounding = (seconds + round_to / 2) // round_to * round_to
else:
if to == 'up':
# // is a floor division, not a comment on following line (like in javascript):
rounding = (seconds + dt.microsecond/1000000 + round_to) // round_to * round_to
elif to == 'down':
rounding = seconds // round_to * round_to
else:
rounding = (seconds + round_to / 2) // round_to * round_to
return dt + datetime.timedelta(0, rounding - seconds, - dt.microsecond)
# test data
print(round_time(datetime.datetime(2019,11,1,14,39,00), date_delta=datetime.timedelta(seconds=30), to='up'))
print(round_time(datetime.datetime(2019,11,2,14,39,00,1), date_delta=datetime.timedelta(seconds=30), to='up'))
print(round_time(datetime.datetime(2019,11,3,14,39,00,776980), date_delta=datetime.timedelta(seconds=30), to='up'))
print(round_time(datetime.datetime(2019,11,4,14,39,29,776980), date_delta=datetime.timedelta(seconds=30), to='up'))
print(round_time(datetime.datetime(2018,11,5,14,39,00,776980), date_delta=datetime.timedelta(seconds=30), to='down'))
print(round_time(datetime.datetime(2018,11,6,14,38,59,776980), date_delta=datetime.timedelta(seconds=30), to='down'))
print(round_time(datetime.datetime(2017,11,7,14,39,15), date_delta=datetime.timedelta(seconds=30), to='average'))
print(round_time(datetime.datetime(2017,11,8,14,39,14,999999), date_delta=datetime.timedelta(seconds=30), to='average'))
print(round_time(datetime.datetime(2019,11,9,14,39,14,999999), date_delta=datetime.timedelta(seconds=30), to='up'))
print(round_time(datetime.datetime(2012,12,10,23,44,59,7769),to='average'))
print(round_time(datetime.datetime(2012,12,11,23,44,59,7769),to='up'))
print(round_time(datetime.datetime(2010,12,12,23,44,59,7769),to='down',date_delta=datetime.timedelta(seconds=1)))
print(round_time(datetime.datetime(2011,12,13,23,44,59,7769),to='up',date_delta=datetime.timedelta(seconds=1)))
print(round_time(datetime.datetime(2012,12,14,23,44,59),date_delta=datetime.timedelta(hours=1),to='down'))
print(round_time(datetime.datetime(2012,12,15,23,44,59),date_delta=datetime.timedelta(hours=1),to='up'))
print(round_time(datetime.datetime(2012,12,16,23,44,59),date_delta=datetime.timedelta(hours=1)))
print(round_time(datetime.datetime(2012,12,17,23,00,00),date_delta=datetime.timedelta(hours=1),to='down'))
print(round_time(datetime.datetime(2012,12,18,23,00,00),date_delta=datetime.timedelta(hours=1),to='up'))
print(round_time(datetime.datetime(2012,12,19,23,00,00),date_delta=datetime.timedelta(hours=1)))
From the best answer I modified to an adapted version using only datetime objects, this avoids having to do the conversion to seconds and makes the calling code more readable:
def roundTime(dt=None, dateDelta=datetime.timedelta(minutes=1)):
"""Round a datetime object to a multiple of a timedelta
dt : datetime.datetime object, default now.
dateDelta : timedelta object, we round to a multiple of this, default 1 minute.
Author: Thierry Husson 2012 - Use it as you want but don't blame me.
Stijn Nevens 2014 - Changed to use only datetime objects as variables
"""
roundTo = dateDelta.total_seconds()
if dt == None : dt = datetime.datetime.now()
seconds = (dt - dt.min).seconds
# // is a floor division, not a comment on following line:
rounding = (seconds+roundTo/2) // roundTo * roundTo
return dt + datetime.timedelta(0,rounding-seconds,-dt.microsecond)
Samples with 1 hour rounding & 15 minutes rounding:
print roundTime(datetime.datetime(2012,12,31,23,44,59),datetime.timedelta(hour=1))
2013-01-01 00:00:00
print roundTime(datetime.datetime(2012,12,31,23,44,49),datetime.timedelta(minutes=15))
2012-12-31 23:30:00
Pandas has a datetime round feature, but as with most things in Pandas it needs to be in Series format.
>>> ts = pd.Series(pd.date_range(Dt(2019,1,1,1,1),Dt(2019,1,1,1,4),periods=8))
>>> print(ts)
0 2019-01-01 01:01:00.000000000
1 2019-01-01 01:01:25.714285714
2 2019-01-01 01:01:51.428571428
3 2019-01-01 01:02:17.142857142
4 2019-01-01 01:02:42.857142857
5 2019-01-01 01:03:08.571428571
6 2019-01-01 01:03:34.285714285
7 2019-01-01 01:04:00.000000000
dtype: datetime64[ns]
>>> ts.dt.round('1min')
0 2019-01-01 01:01:00
1 2019-01-01 01:01:00
2 2019-01-01 01:02:00
3 2019-01-01 01:02:00
4 2019-01-01 01:03:00
5 2019-01-01 01:03:00
6 2019-01-01 01:04:00
7 2019-01-01 01:04:00
dtype: datetime64[ns]
Docs - Change the frequency string as needed.
Here is a simpler generalized solution without floating point precision issues and external library dependencies:
import datetime
def time_mod(time, delta, epoch=None):
if epoch is None:
epoch = datetime.datetime(1970, 1, 1, tzinfo=time.tzinfo)
return (time - epoch) % delta
def time_round(time, delta, epoch=None):
mod = time_mod(time, delta, epoch)
if mod < delta / 2:
return time - mod
return time + (delta - mod)
def time_floor(time, delta, epoch=None):
mod = time_mod(time, delta, epoch)
return time - mod
def time_ceil(time, delta, epoch=None):
mod = time_mod(time, delta, epoch)
if mod:
return time + (delta - mod)
return time
In your case:
>>> tm = datetime.datetime(2010, 6, 10, 3, 56, 23)
>>> time_round(tm, datetime.timedelta(minutes=10))
datetime.datetime(2010, 6, 10, 4, 0)
>>> time_floor(tm, datetime.timedelta(minutes=10))
datetime.datetime(2010, 6, 10, 3, 50)
>>> time_ceil(tm, datetime.timedelta(minutes=10))
datetime.datetime(2010, 6, 10, 4, 0)
if you don't want to use condition, you can use modulo operator:
minutes = int(round(tm.minute, -1)) % 60
UPDATE
did you want something like this?
def timeround10(dt):
a, b = divmod(round(dt.minute, -1), 60)
return '%i:%02i' % ((dt.hour + a) % 24, b)
timeround10(datetime.datetime(2010, 1, 1, 0, 56, 0)) # 0:56
# -> 1:00
timeround10(datetime.datetime(2010, 1, 1, 23, 56, 0)) # 23:56
# -> 0:00
.. if you want result as string. for obtaining datetime result, it's better to use timedelta - see other responses ;)
i'm using this. it has the advantage of working with tz aware datetimes.
def round_minutes(some_datetime: datetime, step: int):
""" round up to nearest step-minutes """
if step > 60:
raise AttrbuteError("step must be less than 60")
change = timedelta(
minutes= some_datetime.minute % step,
seconds=some_datetime.second,
microseconds=some_datetime.microsecond
)
if change > timedelta():
change -= timedelta(minutes=step)
return some_datetime - change
it has the disadvantage of only working for timeslices less than an hour.
A straightforward approach:
def round_time(dt, round_to_seconds=60):
"""Round a datetime object to any number of seconds
dt: datetime.datetime object
round_to_seconds: closest number of seconds for rounding, Default 1 minute.
"""
rounded_epoch = round(dt.timestamp() / round_to_seconds) * round_to_seconds
rounded_dt = datetime.datetime.fromtimestamp(rounded_epoch).astimezone(dt.tzinfo)
return rounded_dt
This will do it, I think it uses a very useful application of round.
from typing import Literal
import math
def round_datetime(dt: datetime.datetime, step: datetime.timedelta, d: Literal['no', 'up', 'down'] = 'no'):
step = step.seconds
round_f = {'no': round, 'up': math.ceil, 'down': math.floor}
return datetime.datetime.fromtimestamp(step * round_f[d](dt.timestamp() / step))
date = datetime.datetime(year=2022, month=11, day=16, hour=10, minute=2, second=30, microsecond=424242)#
print('Original:', date)
print('Standard:', round_datetime(date, datetime.timedelta(minutes=5)))
print('Down: ', round_datetime(date, datetime.timedelta(minutes=5), d='down'))
print('Up: ', round_datetime(date, datetime.timedelta(minutes=5), d='up'))
The result:
Original: 2022-11-16 10:02:30.424242
Standard: 2022-11-16 10:05:00
Down: 2022-11-16 10:00:00
Up: 2022-11-16 10:05:00
yes, if your data belongs to a DateTime column in a pandas series, you can round it up using the built-in pandas.Series.dt.round function.
See documentation here on pandas.Series.dt.round.
In your case of rounding to 10min it will be Series.dt.round('10min') or Series.dt.round('600s') like so:
pandas.Series(tm).dt.round('10min')
Edit to add Example code:
import datetime
import pandas
tm = datetime.datetime(2010, 6, 10, 3, 56, 23)
tm_rounded = pandas.Series(tm).dt.round('10min')
print(tm_rounded)
>>> 0 2010-06-10 04:00:00
dtype: datetime64[ns]
I came up with this very simple function, working with any timedelta as long as it's either a multiple or divider of 60 seconds. It's also compatible with timezone-aware datetimes.
#!/usr/env python3
from datetime import datetime, timedelta
def round_dt_to_delta(dt, delta=timedelta(minutes=30)):
ref = datetime.min.replace(tzinfo=dt.tzinfo)
return ref + round((dt - ref) / delta) * delta
Output:
In [1]: round_dt_to_delta(datetime(2012,12,31,23,44,49), timedelta(seconds=15))
Out[1]: datetime.datetime(2012, 12, 31, 23, 44, 45)
In [2]: round_dt_to_delta(datetime(2012,12,31,23,44,49), timedelta(minutes=15))
Out[2]: datetime.datetime(2012, 12, 31, 23, 45)
General Function to round down times of minutes:
from datetime import datetime
def round_minute(date: datetime = None, round_to: int = 1):
"""
round datetime object to minutes
"""
if not date:
date = datetime.now()
date = date.replace(second=0, microsecond=0)
delta = date.minute % round_to
return date.replace(minute=date.minute - delta)
Those seem overly complex
def round_down_to():
num = int(datetime.utcnow().replace(second=0, microsecond=0).minute)
return num - (num%10)
def get_rounded_datetime(self, dt, freq, nearest_type='inf'):
if freq.lower() == '1h':
round_to = 3600
elif freq.lower() == '3h':
round_to = 3 * 3600
elif freq.lower() == '6h':
round_to = 6 * 3600
else:
raise NotImplementedError("Freq %s is not handled yet" % freq)
# // is a floor division, not a comment on following line:
seconds_from_midnight = dt.hour * 3600 + dt.minute * 60 + dt.second
if nearest_type == 'inf':
rounded_sec = int(seconds_from_midnight / round_to) * round_to
elif nearest_type == 'sup':
rounded_sec = (int(seconds_from_midnight / round_to) + 1) * round_to
else:
raise IllegalArgumentException("nearest_type should be 'inf' or 'sup'")
dt_midnight = datetime.datetime(dt.year, dt.month, dt.day)
return dt_midnight + datetime.timedelta(0, rounded_sec)
Based on Stijn Nevens and modified for Django use to round current time to the nearest 15 minute.
from datetime import date, timedelta, datetime, time
def roundTime(dt=None, dateDelta=timedelta(minutes=1)):
roundTo = dateDelta.total_seconds()
if dt == None : dt = datetime.now()
seconds = (dt - dt.min).seconds
# // is a floor division, not a comment on following line:
rounding = (seconds+roundTo/2) // roundTo * roundTo
return dt + timedelta(0,rounding-seconds,-dt.microsecond)
dt = roundTime(datetime.now(),timedelta(minutes=15)).strftime('%H:%M:%S')
dt = 11:45:00
if you need full date and time just remove the .strftime('%H:%M:%S')
Not the best for speed when the exception is caught, however this would work.
def _minute10(dt=datetime.utcnow()):
try:
return dt.replace(minute=round(dt.minute, -1))
except ValueError:
return dt.replace(minute=0) + timedelta(hours=1)
Timings
%timeit _minute10(datetime(2016, 12, 31, 23, 55))
100000 loops, best of 3: 5.12 µs per loop
%timeit _minute10(datetime(2016, 12, 31, 23, 31))
100000 loops, best of 3: 2.21 µs per loop
A two line intuitive solution to round to a given time unit, here seconds, for a datetime object t:
format_str = '%Y-%m-%d %H:%M:%S'
t_rounded = datetime.strptime(datetime.strftime(t, format_str), format_str)
If you wish to round to a different unit simply alter format_str.
This approach does not round to arbitrary time amounts as above methods, but is a nicely Pythonic way to round to a given hour, minute or second.
Other solution:
def round_time(timestamp=None, lapse=0):
"""
Round a timestamp to a lapse according to specified minutes
Usage:
>>> import datetime, math
>>> round_time(datetime.datetime(2010, 6, 10, 3, 56, 23), 0)
datetime.datetime(2010, 6, 10, 3, 56)
>>> round_time(datetime.datetime(2010, 6, 10, 3, 56, 23), 1)
datetime.datetime(2010, 6, 10, 3, 57)
>>> round_time(datetime.datetime(2010, 6, 10, 3, 56, 23), -1)
datetime.datetime(2010, 6, 10, 3, 55)
>>> round_time(datetime.datetime(2019, 3, 11, 9, 22, 11), 3)
datetime.datetime(2019, 3, 11, 9, 24)
>>> round_time(datetime.datetime(2019, 3, 11, 9, 22, 11), 3*60)
datetime.datetime(2019, 3, 11, 12, 0)
>>> round_time(datetime.datetime(2019, 3, 11, 10, 0, 0), 3)
datetime.datetime(2019, 3, 11, 10, 0)
:param timestamp: Timestamp to round (default: now)
:param lapse: Lapse to round in minutes (default: 0)
"""
t = timestamp or datetime.datetime.now() # type: Union[datetime, Any]
surplus = datetime.timedelta(seconds=t.second, microseconds=t.microsecond)
t -= surplus
try:
mod = t.minute % lapse
except ZeroDivisionError:
return t
if mod: # minutes % lapse != 0
t += datetime.timedelta(minutes=math.ceil(t.minute / lapse) * lapse - t.minute)
elif surplus != datetime.timedelta() or lapse < 0:
t += datetime.timedelta(minutes=(t.minute / lapse + 1) * lapse - t.minute)
return t
Hope this helps!
The shortest way I know
min = tm.minute // 10 * 10
Most of the answers seem to be too complicated for such a simple question.
Assuming your_time is the datetime object your have, the following rounds (actually floors) it at a desired resolution defined in minutes.
from math import floor
your_time = datetime.datetime.now()
g = 10 # granularity in minutes
print(
datetime.datetime.fromtimestamp(
floor(your_time.timestamp() / (60*g)) * (60*g)
))
The function below with minimum of import will do the job. You can round to anything you want by setting te parameters unit, rnd, and frm. Play with the function and you will see how easy it will be.
def toNearestTime(ts, unit='sec', rnd=1, frm=None):
''' round to nearest Time format
param ts = time string to round in '%H:%M:%S' or '%H:%M' format :
param unit = specify unit wich must be rounded 'sec' or 'min' or 'hour', default is seconds :
param rnd = to which number you will round, the default is 1 :
param frm = the output (return) format of the time string, as default the function take the unit format'''
from time import strftime, gmtime
ts = ts + ':00' if len(ts) == 5 else ts
if 'se' in unit.lower():
frm = '%H:%M:%S' if frm is None else frm
elif 'm' in unit.lower():
frm = '%H:%M' if frm is None else frm
rnd = rnd * 60
elif 'h' in unit.lower():
frm = '%H' if frm is None else frm
rnd = rnd * 3600
secs = sum(int(x) * 60 ** i for i, x in enumerate(reversed(ts.split(':'))))
rtm = int(round(secs / rnd, 0) * rnd)
nt = strftime(frm, gmtime(rtm))
return nt
Call function as follow:
Round to nearest 5 minutes with default ouput format = hh:mm as follow
ts = '02:27:29'
nt = toNearestTime(ts, unit='min', rnd=5)
print(nt)
output: '02:25'
Or round to nearest hour with ouput format hh:mm:ss as follow
ts = '10:30:01'
nt = toNearestTime(ts, unit='hour', rnd=1, frm='%H:%M:%S')
print(nt)
output: '11:00:00'
last updated version
Sure I could write this myself, but before I go reinventing the wheel is there a function that already does this?
Given an instance x of datetime.date, (x.month-1)//3 will give you the quarter (0 for first quarter, 1 for second quarter, etc -- add 1 if you need to count from 1 instead;-).
Originally two answers, multiply upvoted and even originally accepted (both currently deleted), were buggy -- not doing the -1 before the division, and dividing by 4 instead of 3. Since .month goes 1 to 12, it's easy to check for yourself what formula is right:
for m in range(1, 13):
print m//4 + 1,
print
gives 1 1 1 2 2 2 2 3 3 3 3 4 -- two four-month quarters and a single-month one (eep).
for m in range(1, 13):
print (m-1)//3 + 1,
print
gives 1 1 1 2 2 2 3 3 3 4 4 4 -- now doesn't this look vastly preferable to you?-)
This proves that the question is well warranted, I think;-).
I don't think the datetime module should necessarily have every possible useful calendric function, but I do know I maintain a (well-tested;-) datetools module for the use of my (and others') projects at work, which has many little functions to perform all of these calendric computations -- some are complex, some simple, but there's no reason to do the work over and over (even simple work) or risk bugs in such computations;-).
IF you are already using pandas, it's quite simple.
import datetime as dt
import pandas as pd
quarter = pd.Timestamp(dt.date(2016, 2, 29)).quarter
assert quarter == 1
If you have a date column in a dataframe, you can easily create a new quarter column:
df['quarter'] = df['date'].dt.quarter
I would suggest another arguably cleaner solution. If X is a datetime.datetime.now() instance, then the quarter is:
import math
Q=math.ceil(X.month/3.)
ceil has to be imported from math module as it can't be accessed directly.
For anyone trying to get the quarter of the fiscal year, which may differ from the calendar year, I wrote a Python module to do just this.
Installation is simple. Just run:
$ pip install fiscalyear
There are no dependencies, and fiscalyear should work for both Python 2 and 3.
It's basically a wrapper around the built-in datetime module, so any datetime commands you are already familiar with will work. Here's a demo:
>>> from fiscalyear import *
>>> a = FiscalDate.today()
>>> a
FiscalDate(2017, 5, 6)
>>> a.fiscal_year
2017
>>> a.quarter
3
>>> b = FiscalYear(2017)
>>> b.start
FiscalDateTime(2016, 10, 1, 0, 0)
>>> b.end
FiscalDateTime(2017, 9, 30, 23, 59, 59)
>>> b.q3
FiscalQuarter(2017, 3)
>>> b.q3.start
FiscalDateTime(2017, 4, 1, 0, 0)
>>> b.q3.end
FiscalDateTime(2017, 6, 30, 23, 59, 59)
fiscalyear is hosted on GitHub and PyPI. Documentation can be found at Read the Docs. If you're looking for any features that it doesn't currently have, let me know!
This is very simple and works in python3:
from datetime import datetime
# Get current date-time.
now = datetime.now()
# Determine which quarter of the year is now. Returns q1, q2, q3 or q4.
quarter_of_the_year = f'q{(now.month-1)//3+1}'
if m is the month number...
import math
math.ceil(float(m) / 3)
This method works for any mapping:
month2quarter = {
1:1,2:1,3:1,
4:2,5:2,6:2,
7:3,8:3,9:3,
10:4,11:4,12:4,
}.get
We have just generated a function int->int
month2quarter(9) # returns 3
This method is also fool-proof
month2quarter(-1) # returns None
month2quarter('July') # returns None
Here is an example of a function that gets a datetime.datetime object and returns a unique string for each quarter:
from datetime import datetime, timedelta
def get_quarter(d):
return "Q%d_%d" % (math.ceil(d.month/3), d.year)
d = datetime.now()
print(d.strftime("%Y-%m-%d"), get_q(d))
d2 = d - timedelta(90)
print(d2.strftime("%Y-%m-%d"), get_q(d2))
d3 = d - timedelta(180 + 365)
print(d3.strftime("%Y-%m-%d"), get_q(d3))
And the output is:
2019-02-14 Q1_2019
2018-11-16 Q4_2018
2017-08-18 Q3_2017
For those, who are looking for financial year quarter data,
using pandas,
import datetime
import pandas as pd
today_date = datetime.date.today()
quarter = pd.PeriodIndex(today_date, freq='Q-MAR').strftime('Q%q')
reference:
pandas period index
This is an old question but still worthy of discussion.
Here is my solution, using the excellent dateutil module.
from dateutil import rrule,relativedelta
year = this_date.year
quarters = rrule.rrule(rrule.MONTHLY,
bymonth=(1,4,7,10),
bysetpos=-1,
dtstart=datetime.datetime(year,1,1),
count=8)
first_day = quarters.before(this_date)
last_day = (quarters.after(this_date)
-relativedelta.relativedelta(days=1)
So first_day is the first day of the quarter, and last_day is the last day of the quarter (calculated by finding the first day of the next quarter, minus one day).
I tried the solution with x//3+1 and x//4+1,
We get incorrect quarter in either case.
The correct answer is like this
for i in range(1,13):
print(((i-1)//3)+1)
import datetime
def get_quarter_number_and_date_from_choices(p_quarter_choice):
"""
:param p_quarter_choice:
:return:
"""
current_date = datetime.date.today()
# current_quarter = current_date.month - 1 // 3 + 1
if p_quarter_choice == 'Q1':
quarter = 1
q_start_date = datetime.datetime(current_date.year, 3 * quarter - 2, 1)
q_end_date = datetime.datetime(current_date.year, 3 * quarter + 1, 1) + datetime.timedelta(days=-1)
return q_start_date, q_end_date
elif p_quarter_choice == 'Q2':
quarter = 2
q_start_date = datetime.datetime(current_date.year, 3 * quarter - 2, 1)
q_end_date = datetime.datetime(current_date.year, 3 * quarter + 1, 1) + datetime.timedelta(days=-1)
return q_start_date, q_end_date
elif p_quarter_choice == 'Q3':
quarter = 3
q_start_date = datetime.datetime(current_date.year, 3 * quarter - 2, 1)
q_end_date = datetime.datetime(current_date.year, 3 * quarter + 1, 1) + datetime.timedelta(days=-1)
return q_start_date, q_end_date
elif p_quarter_choice == 'Q4':
quarter = 4
q_start_date = datetime.datetime(current_date.year, 3 * quarter - 2, 1)
q_end_date = datetime.datetime(current_date.year, 3 * quarter, 1) + datetime.timedelta(days=30)
return q_start_date, q_end_date
return None
hmmm so calculations can go wrong, here is a better version (just for the sake of it)
first, second, third, fourth=1,2,3,4# you can make strings if you wish :)
quarterMap = {}
quarterMap.update(dict(zip((1,2,3),(first,)*3)))
quarterMap.update(dict(zip((4,5,6),(second,)*3)))
quarterMap.update(dict(zip((7,8,9),(third,)*3)))
quarterMap.update(dict(zip((10,11,12),(fourth,)*3)))
print quarterMap[6]
Here is a verbose, but also readable solution that will work for datetime and date instances
def get_quarter(date):
for months, quarter in [
([1, 2, 3], 1),
([4, 5, 6], 2),
([7, 8, 9], 3),
([10, 11, 12], 4)
]:
if date.month in months:
return quarter
using dictionaries, you can pull this off by
def get_quarter(month):
quarter_dictionary = {
"Q1" : [1,2,3],
"Q2" : [4,5,6],
"Q3" : [7,8,9],
"Q4" : [10,11,12]
}
for key,values in quarter_dictionary.items():
for value in values:
if value == month:
return key
print(get_quarter(3))
for m in range(1, 13):
print ((m*3)//10)
A revisited solution using #Alex Martelli formula and creting a quick function as the question asks.
from datetime import timedelta, date
date_from = date(2021, 1, 1)
date_to = date(2021, 12, 31)
get_quarter = lambda dt: (dt.month-1)//3 + 1
quarter_from = get_quarter(date_from)
quarter_to = get_quarter(date_to)
print(quarter_from)
print(quarter_to)
# 1
# 4
def euclid(a,b):
r = a % b
q = int( ( (a + b - 1) - (a - 1) % b ) / b )
return(q,r)
months_per_year = 12
months_per_quarter = 3
for i in range(months_per_year):
print(i+1,euclid(i+1,months_per_quarter)[0])
#1 1
#2 1
#3 1
#4 2
#5 2
#6 2
#7 3
#8 3
#9 3
#10 4
#11 4
#12 4