Given a datetime object, how do I round it up to the next occurrence of 8AM PST?
If the result is a timezone-aware datetime object in a timezone with a non-fixed UTC offset then you can't just call .replace() or .combine() -- it may create a datetime with a wrong UTC offset. The issue is similar to How do I get the UTC time of "midnight" for a given timezone? (00:00 is used instead of 08:00).
Assuming 8AM always exists and unambiguous in PST:
from datetime import datetime, time as datetime_time, timedelta
import pytz # $ pip install pytz
def next_8am_in_pst(aware_dt, tz=pytz.timezone('America/Los_Angeles')):
pst_aware_dt = tz.normalize(aware_dt.astimezone(tz)) # convert to PST
naive_dt = round_up_to_8am(pst_aware_dt.replace(tzinfo=None))
return tz.localize(naive_dt, is_dst=None)
def round_up_to_8am(dt):
rounded = datetime.combine(dt, datetime_time(8))
return rounded + timedelta(rounded < dt)
Example:
>>> str(next_8am_in_pst(datetime.now(pytz.utc)))
'2016-02-25 08:00:00-08:00'
Just test whether the time is before or after 8, then add a day if it's after and construct a new datetime.
import datetime
def round_datetime(dt):
t = datetime.time(8)
# If time is after 8am, add a day.
if dt.time() > datetime.time(8):
dt += datetime.timedelta(days=1)
return datetime.datetime.combine(dt, t)
I made an answer based on some ideas from the comments:
def nextDay(d):
pstTime = d.astimezone(pytz.timezone('US/Pacific'))
pstTime = pstTime.replace(hour=8, minute=0, second=0, microsecond=0)
if pstTime < d:
pstTime += datetime.timedelta(days=1)
return pstTime
Related
Kindly help below my query:
I got an estimated time from API server like below:
2019-09-25T20:11:23+08:00
it seems like iso 8601 standard with timezone.
I would like to know how to calculate how many days, hours, minutes and seconds left from above value to the current time.
import datetime
Receved_time_frim_API = "2019-09-25T20:11:23+08:00"
Current_time = datetime.datetime.now()
left_days =
left_hour =
left_min =
left_sec =
Your time string contains timezone info. According to https://stackoverflow.com/a/13182163/12112986 it's easy to convert it to datetime object in python 3.7
import datetime
received = datetime.datetime.fromisoformat(Receved_time_frim_API)
In previous versions there is no easy oneliner to convert string with timezone to datetime object. If you're using earlier python version, you can try something crude, like
>>> date, timezone = Receved_time_frim_API.split("+")
>>> tz_hours, tz_minutes = timezone.split(":")
>>> date = datetime.datetime.strptime(date, "%Y-%m-%dT%H:%M:%S")
>>> date -= datetime.timedelta(hours=int(tz_hours))
>>> date -= datetime.timedelta(minutes=int(tz_minutes))
Note that this will work only in case of positive timezones
To substract two datetime objects use
td = date - Current_time
left_days = td.days
left_hour = td.seconds // 3600
left_min = (td.seconds//60)%60
left_sec = td.seconds % 60
Okay first you need to parse the Receved_time_frim_API into datetime format:
from dateutil import parser
Receved_time_frim_API = parser.parse("2019-09-25T20:11:23+08:00")
But you can't just substract this from your Current_time, because datetime.now() is not aware of a timezone:
from datetime import timezone
Current_time = datetime.datetime.now().replace(tzinfo=timezone.utc)
print (Current_time-Receved_time_frim_API)
The result is a datetime.timedelta
I am able to get the current time as below:
from datetime import datetime
str(datetime.now())[11:19]
Result
'19:43:20'
Now, I am trying to add 9 hours to the above time, how can I add hours to current time in Python?
from datetime import datetime, timedelta
nine_hours_from_now = datetime.now() + timedelta(hours=9)
#datetime.datetime(2012, 12, 3, 23, 24, 31, 774118)
And then use string formatting to get the relevant pieces:
>>> '{:%H:%M:%S}'.format(nine_hours_from_now)
'23:24:31'
If you're only formatting the datetime then you can use:
>>> format(nine_hours_from_now, '%H:%M:%S')
'23:24:31'
Or, as #eumiro has pointed out in comments - strftime
Import datetime and timedelta:
>>> from datetime import datetime, timedelta
>>> str(datetime.now() + timedelta(hours=9))[11:19]
'01:41:44'
But the better way is:
>>> (datetime.now() + timedelta(hours=9)).strftime('%H:%M:%S')
'01:42:05'
You can refer strptime and strftime behavior to better understand how python processes dates and time field
This works for me working with seconds not hours and also using a function to convert back to UTC time.
from datetime import timezone, datetime, timedelta
import datetime
def utc_converter(dt):
dt = datetime.datetime.now(timezone.utc)
utc_time = dt.replace(tzinfo=timezone.utc)
utc_timestamp = utc_time.timestamp()
return utc_timestamp
# create start and end timestamps
_now = datetime.datetime.now()
str_start = str(utc_converter(_now))
_end = _now + timedelta(seconds=10)
str_end = str(utc_converter(_end))
This is an answer which is significant for nowadays (python 3.9 or later).
Use strptime to create a datetime object from the timestring. Add 9 hours with timedelta, and match the time format with the timestring you have.
from datetime import datetime, timedelta
from zoneinfo import ZoneInfo
time_format = "%H:%M:%S"
timestring = datetime.strptime(str(datetime.now() + timedelta(hours=9))[11:19], time_format)
#You can then apply custom time formatting as well as a timezone.
TIMEZONE = [Add a timezone] #https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
custom_time_format = "%H:%M"
time_modification = datetime.fromtimestamp(timestring.timestamp(), ZoneInfo(TIMEZONE)).__format__(custom_time_format)
While I think it's more meaningful to apply a timezone, you don't necessarily need to, so you can also simply do that:
time_format = "%H:%M:%S"
timestring = datetime.strptime(str(datetime.now() + timedelta(hours=9))[11:19], time_format)
time_modification = datetime.fromtimestamp(timestring.timestamp())
datetime
https://docs.python.org/3/library/datetime.html
strftime-and-strptime-format-codes
https://docs.python.org/3/library/datetime.html#strftime-and-strptime-format-codes
timedelta
https://docs.python.org/3/library/datetime.html#datetime.timedelta
zoneinfo
https://docs.python.org/3/library/zoneinfo.html#module-zoneinfo
I'm modifying our pacific time zone filter to include a time option. I don't want the time component to be shown if midnight. The only import thus far we are using is dateutil.parser. Any pointers on best solution would be appreciated! Thanks.
def to_pacific_date_str(timestamp, format='%Y-%m-%d', time=False):
pacific_timestamp = timestamp
if time:
format='%Y-%m-%d %H:%M' # 2016-10-03 00:00
if timestamp.tzname() is None:
# setting timezone lost when pulled from DB
utc_timestamp = timestamp.replace(tzinfo=pytz.utc)
# always converting to pacific timezone
pacific_timestamp = utc_timestamp.astimezone(pytz.timezone('US/Pacific'))
return pacific_timestamp.strftime(format)
I believe the best thing to do would be to just take the time() from the datetime before passing it, then compare that to datetime.time(0, 0).
import pytz
import datetime
def to_pacific_date_str(timestamp, date_fmt='%Y-%m-%d', time=False):
pacific_timestamp = timestamp
if timestamp.tzinfo is None:
# setting timezone lost when pulled from DB
utc_timestamp = timestamp.replace(tzinfo=pytz.utc)
# always converting to pacific timezone
pacific_timestamp = utc_timestamp.astimezone(pytz.timezone('US/Pacific'))
if time and pacific_timestamp.time() != datetime.time(0, 0):
date_fmt = '%Y-%m-%d %H:%M' # 2016-10-03 00:00
return pacific_timestamp.strftime(date_fmt)
Note that I've changed format to date_fmt, because format() is already a builtin. Also, from a design standpoint, it's probably not a great idea to have time override the specified format string, so maybe change the "add time" portion to be date_fmt = date_fmt + ' %H:%M'.
Demonstration:
>>> PST = pytz.timezone('US/Pacific')
>>> to_pacific_date_str(PST.localize(datetime.datetime(2015, 4, 1, 0, 0)), time=True)
'2015-04-01'
>>> PST = pytz.timezone('US/Pacific')
>>> to_pacific_date_str(PST.localize(datetime.datetime(2015, 4, 1, 2, 0)), time=True)
'2015-04-01 02:00'
Try this for UTC:
def checkIfMidnight():
return (time.time() % 86400) == 0
To check if the time is midnight:
from datetime import datetime
def checkIfMidnight():
now = datetime.now()
seconds_since_midnight = (now - now.replace(hour=0, minute=0, second=0, microsecond=0)).total_seconds()
return seconds_since_midnight == 0
Alternatively you can use the .hour, .minute and .second attributes of the datetime object. Like this:
from datetime import datetime as dt
from pytz import timezone
now = dt.now(timezone('US/Pacific'))
midnight = now.hour == 0 and now.minute == 0 and now.second == 0 and now.microsecond == 0
midnight is a boolean indicating if it is midnight in the US/Pacific timezone.
I am not sure if this is the solution you are/were looking for but personally I use simple comparison:
import datetime
...
time == datetime.time(hour=0, minute=0, second=0, microsecond=0)
where time is TimeObject (datetime.time)
Here is my code
>>>from datetime import datetime
>>>from dateutil import tz
>>>current_time = datetime.utcnow().replace(tzinfo=tz.gettz('Asia/Calcutta'))
>>>2013-05-12 17:11:36.362000+05:30
i don't want offset-aware i want to add time difference to my current time
so the time will be
>>>2013-05-12 22:41:36.362000
so that i will be able to get time difference from by simply.
>>> datetime.utcnow() - current_time
Thanks,
You can obtain the offset with as a datetime.timedelta using:
offset = current_time.utcoffset()
The offset can then be added or subtracted from the current_time to obtain the desired datetime.
import datetime as DT
import dateutil.tz as tz
import dateutil
current_time = DT.datetime.utcnow().replace(tzinfo=tz.gettz('Asia/Calcutta'))
print(current_time)
# 2013-05-12 18:33:19.368122+05:30
offset = current_time.utcoffset()
naive_time = current_time.replace(tzinfo=None)
print(naive_time)
# 2013-05-12 18:33:19.368122
print(naive_time + offset)
# 2013-05-13 00:03:19.368122
Note that if you want the UTC time, you should subtract the offset:
print(naive_time - offset)
# 2013-05-12 13:03:19.368122
A simpler way to get the UTC datetime would be to use the astimezone method however:
utc = dateutil.tz.tzutc()
print(current_time.astimezone(utc))
# 2013-05-12 13:03:19.368122+00:00
Finally, note that using dateutil and replace to set the timezone does not always return the correct time. Here is how you could do it with pytz:
import pytz
calcutta = pytz.timezone('Asia/Calcutta')
utc = pytz.utc
current_time = calcutta.localize(DT.datetime.utcnow())
print(current_time)
# 2013-05-12 18:33:19.368705+05:30
print(current_time.astimezone(utc))
# 2013-05-12 13:03:19.368705+00:00
You can get the offset by using datetime.utcoffset()
current_time = datetime.utcnow().replace(tzinfo=tz.gettz('Asia/Calcutta'))
td = datetime.utcoffset(current_time)
#datetime.timedelta(0, 19800)
td.total_seconds() / 3600
#5.5
I am able to get the current time as below:
from datetime import datetime
str(datetime.now())[11:19]
Result
'19:43:20'
Now, I am trying to add 9 hours to the above time, how can I add hours to current time in Python?
from datetime import datetime, timedelta
nine_hours_from_now = datetime.now() + timedelta(hours=9)
#datetime.datetime(2012, 12, 3, 23, 24, 31, 774118)
And then use string formatting to get the relevant pieces:
>>> '{:%H:%M:%S}'.format(nine_hours_from_now)
'23:24:31'
If you're only formatting the datetime then you can use:
>>> format(nine_hours_from_now, '%H:%M:%S')
'23:24:31'
Or, as #eumiro has pointed out in comments - strftime
Import datetime and timedelta:
>>> from datetime import datetime, timedelta
>>> str(datetime.now() + timedelta(hours=9))[11:19]
'01:41:44'
But the better way is:
>>> (datetime.now() + timedelta(hours=9)).strftime('%H:%M:%S')
'01:42:05'
You can refer strptime and strftime behavior to better understand how python processes dates and time field
This works for me working with seconds not hours and also using a function to convert back to UTC time.
from datetime import timezone, datetime, timedelta
import datetime
def utc_converter(dt):
dt = datetime.datetime.now(timezone.utc)
utc_time = dt.replace(tzinfo=timezone.utc)
utc_timestamp = utc_time.timestamp()
return utc_timestamp
# create start and end timestamps
_now = datetime.datetime.now()
str_start = str(utc_converter(_now))
_end = _now + timedelta(seconds=10)
str_end = str(utc_converter(_end))
This is an answer which is significant for nowadays (python 3.9 or later).
Use strptime to create a datetime object from the timestring. Add 9 hours with timedelta, and match the time format with the timestring you have.
from datetime import datetime, timedelta
from zoneinfo import ZoneInfo
time_format = "%H:%M:%S"
timestring = datetime.strptime(str(datetime.now() + timedelta(hours=9))[11:19], time_format)
#You can then apply custom time formatting as well as a timezone.
TIMEZONE = [Add a timezone] #https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
custom_time_format = "%H:%M"
time_modification = datetime.fromtimestamp(timestring.timestamp(), ZoneInfo(TIMEZONE)).__format__(custom_time_format)
While I think it's more meaningful to apply a timezone, you don't necessarily need to, so you can also simply do that:
time_format = "%H:%M:%S"
timestring = datetime.strptime(str(datetime.now() + timedelta(hours=9))[11:19], time_format)
time_modification = datetime.fromtimestamp(timestring.timestamp())
datetime
https://docs.python.org/3/library/datetime.html
strftime-and-strptime-format-codes
https://docs.python.org/3/library/datetime.html#strftime-and-strptime-format-codes
timedelta
https://docs.python.org/3/library/datetime.html#datetime.timedelta
zoneinfo
https://docs.python.org/3/library/zoneinfo.html#module-zoneinfo