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Python convert timestamp to unix

I know these questions have been asked before but I'm struggling to convert a timestamp string to a unix time and figuring out whether the datetime objects are naive or aware
For example, to convert the time "2021-05-19 12:51:47" to unix:
>>> from datetime import datetime as dt
>>> dt_obj = dt.strptime("2021-05-19 12:51:47", "%Y-%m-%d %H:%M:%S")
>>> dt_obj
datetime.datetime(2021, 5, 19, 12, 51, 47)
is dt_obj naive or aware and how would you determine this? The methods on dt_obj such as timetz, tzinfo, and tzname don't seem to indicate anything - does that mean that dt_obj is naive?
Then to get unix:
>>> dt_obj.timestamp()
1621421507.0
However when I check 1621421507.0 on say https://www.unixtimestamp.com then it tells me that gmt for the above is Wed May 19 2021 10:51:47 GMT+0000, ie 2 hours behind the original timestamp?

since Python's datetime treats naive datetime as local time by default, you need to set the time zone (tzinfo attribute):
from datetime import datetime, timezone
# assuming "2021-05-19 12:51:47" represents UTC:
dt_obj = datetime.fromisoformat("2021-05-19 12:51:47").replace(tzinfo=timezone.utc)
Or, as #Wolf suggested, instead of setting the tzinfo attribute explicitly, you can also modify the input string by adding "+00:00" which is parsed to UTC;
dt_obj = datetime.fromisoformat("2021-05-19 12:51:47" + "+00:00")
In any case, the result
dt_obj.timestamp()
# 1621428707.0
now converts as expected on https://www.unixtimestamp.com/:

As long as you don't specify the timezone when calling strptime, you will produce naive datetime objects. You may pass time zone information via %z format specifier and +00:00 added to the textual date-time representation to get a timezone aware datetime object:
from datetime import datetime
dt_str = "2021-05-19 12:51:47"
print(dt_str)
dt_obj = datetime.strptime(dt_str+"+00:00", "%Y-%m-%d %H:%M:%S%z")
print(dt_obj)
print(dt_obj.timestamp())
The of above script is this:
2021-05-19 12:51:47
2021-05-19 12:51:47+00:00
1621428707.0

datetime.timestamp()
Naive datetime instances are assumed to represent local time and this method relies on the platform C mktime() function to perform the conversion.
So using this does automatically apply yours machine current timezone, following recipe is given to calculate timestamp from naive datetime without influence of timezone:
timestamp = (dt - datetime(1970, 1, 1)) / timedelta(seconds=1)

How to convert python timestamp string to epoch?

I have the following string:
mytime = "2009-03-08T00:27:31.807Z"
How do I convert it to epoch in python?
I tried:
import time
p = '%Y-%m-%dT%H:%M:%S'
int(time.mktime(time.strptime(s, p)))
But it does not work with the 31.807Z.

There are two parts:
Convert the time string into a broken-down time. See How to parse ISO formatted date in python?
Convert the UTC time to "seconds since the Epoch" (POSIX timestamp).
#!/usr/bin/env python
from datetime import datetime
utc_time = datetime.strptime("2009-03-08T00:27:31.807Z", "%Y-%m-%dT%H:%M:%S.%fZ")
epoch_time = (utc_time - datetime(1970, 1, 1)).total_seconds()
# -> 1236472051.807
If you are sure that you want to ignore fractions of a second and to get an integer result:
#!/usr/bin/env python
import time
from calendar import timegm
utc_time = time.strptime("2009-03-08T00:27:31.807Z", "%Y-%m-%dT%H:%M:%S.%fZ")
epoch_time = timegm(utc_time)
# -> 1236472051
To support timestamps that correspond to a leap second such as Wed July 1 2:59:60 MSK 2015, you could use a combination of time.strptime() and datetime (if you care about leap seconds you should take into account the microseconds too).

You are missing .%fZ from your format string.
p = '%Y-%m-%dT%H:%M:%S.%fZ'
The correct way to convert to epoch is to use datetime:
from datetime import datetime
p = '%Y-%m-%dT%H:%M:%S.%fZ'
mytime = "2009-03-08T00:27:31.807Z"
epoch = datetime(1970, 1, 1)
print((datetime.strptime(mytime, p) - epoch).total_seconds())
Or call int if you want to ignore fractions.

dateutil has recently been added back to python packages, it's an easy one liner that handles formatting on its own.
from dateutil import parser
strtime = '2009-03-08T00:27:31.807Z'
epoch = parser.parse(strtime).timestamp()

dateutil is the only library i have found that correctly deals with the timezone offset identitifier (Z)
pip install python-dateutil
then
from dateutil.parser import parse as date_parse
print date_parse("2009-03-08T00:27:31.807Z")
#get timestamp
import calendar
dt = date_parse("2009-03-08T00:27:31.807Z")
timestamp1 = calendar.timegm(dt.timetuple())

Code:
import datetime
epoch = datetime.datetime(1970, 1, 1)
mytime = "2009-03-08T00:27:31.807Z"
myformat = "%Y-%m-%dT%H:%M:%S.%fZ"
mydt = datetime.datetime.strptime(mytime, myformat)
val = (mydt - epoch).total_seconds()
print(val)
> 1236472051.81
repr(val)
> '1236472051.807'
Notes:
When using time.strptime(), the returned time.struct_time does not support sub-second precision.
The %f format is for microseconds. When parsing it need not be the full 6 digits.

Python 3.7+ The string format in question can be parsed by strptime:
from datetime import datetime
datetime.strptime("2009-03-08T00:27:31.807Z", '%Y-%m-%dT%H:%M:%S.%f%z')
>>> datetime.datetime(2009, 3, 8, 0, 27, 31, 807000, tzinfo=datetime.timezone.utc)
Another option using the built-in datetime.fromisoformat(): As mentioned in this thread linked by #jfs, fromisoformat() doesn't parse the 'Z' character to UTC although this is part of the RFC3339 definitions. A little work-around can make it work - some will consider this nasty but it's efficient after all.
from datetime import datetime
mytime = "2009-03-08T00:27:31.807Z"
datetime.fromisoformat(mytime.replace("Z", "+00:00")).timestamp()
>>> 1236472051.807

This code works in Python 3.6 to convert a datetime string to epoch in UTC or local timezone.
from datetime import datetime, timedelta
from dateutil.tz import tzutc, tzlocal
mydate = '2020-09-25'
mytime = '06:00:00'
epoch1970 = datetime(1970, 1, 1, 0, 0, 0, tzinfo=tzutc())
myepochutc = int((datetime.strptime(mydate + ' ' + mytime, "%Y-%m-%d %H:%M:%S").replace(tzinfo=tzutc()) - epoch1970).total_seconds()*1000)
myepochlocal = int((datetime.strptime(mydate + ' ' + mytime, "%Y-%m-%d %H:%M:%S").replace(tzinfo=tzlocal()) - epoch1970).total_seconds()*1000)
#epoch will be in milliseconds
print(myepochutc) #if mydate/mytime was in utc
print(myepochlocal) #if mydate/mytime was in local timezone

Specify which timezone a datetime is in, in python

I have a datetime that i get from a database, this datetime is a UTC datetime. But when i pull it from the DB, it is unaware of the timezone. What i need to do, is convert this datetime to a "seconds from epoch" time for another function. The problem with this, is that the system's time is in PST and i am not able to change it for specific reasons.
So, what i want to do is, take this datetime that i get from the database, and tell python that this datetime is a UTC datetime. Every way that i have done that, results in it losing time or gaining time due to timezone conversions. Again, not trying to convert the time, just trying to specify that it is UTC.
If anyone can help with this that would be great.
Thanks!
Example
Assume database_function() returns a datetime data type that is '2013-06-01 01:06:18'
datetime = database_function()
epoch = datetime.strftime('%s')
pytz.utc.localize(database_function()).datetime.strftime('%s')
datetime.replace(tzinfo=pytz.utc).datetime.strftime('%s')
Both of these return a epoch timestamp of 1370077578
But, it SHOULD return a timestamp of 1370048778 per http://www.epochconverter.com/
Remember, this timestamp is a utc timestamp

Using the fabolous pytz:
import datetime, pytz
dt = datetime.datetime(...)
utc_dt = pytz.utc.localize(dt)
This creates a tz-aware datetime object, in UTC.

How about Setting timezone in Python This appears to reset the timezone within your python script. You are changing the time zone that your system sees given the specified time, not changing the specified time into the specified time zone. You probably want to set it to 'UTC'
time.tzset()
Resets the time conversion rules used by the library routines.
The environment variable TZ specifies how this is done.
New in version 2.3.
Availability: Unix.
I do not have this available on my home platform so I could not test it. I had to get this from the previous answer.
The answer marked best on the question is:
>>> import os, time
>>> time.strftime('%X %x %Z')
'12:45:20 08/19/09 CDT'
>>> os.environ['TZ'] = 'Europe/London'
>>> time.tzset()
>>> time.strftime('%X %x %Z')
'18:45:39 08/19/09 BST'
To get the specific values you've listed:
>>> year = time.strftime('%Y')
>>> month = time.strftime('%m')
>>> day = time.strftime('%d')
>>> hour = time.strftime('%H')
>>> minute = time.strftime('%M')
See here for a complete list of directives. Keep in mind that the strftime() function will always return a string, not an integer or other type.

You can Use pytz, which is a time zone definitions package.
from datetime import datetime
from pytz import timezone
fmt = "%Y-%m-%d %H:%M:%S %Z%z"
# Current time in UTC
now_utc = datetime.now(timezone('UTC'))
print now_utc.strftime(fmt)
# Convert to US/Pacific time zone
now_pacific = now_utc.astimezone(timezone('US/Pacific'))
print now_pacific.strftime(fmt)
# Convert to Europe/Berlin time zone
now_berlin = now_pacific.astimezone(timezone('Europe/Berlin'))
print now_berlin.strftime(fmt)
output:
2014-04-04 21:50:55 UTC+0000
2014-04-04 14:50:55 PDT-0700
2014-04-04 23:50:55 CEST+0200
or may be it helps
>> import pytz
>>> import datetime
>>>
>>> now_utc = datetime.datetime.utcnow() #Our UTC naive time from DB,
for the time being here I'm taking it as current system UTC time..
>>> now_utc
datetime.datetime(2011, 5, 9, 6, 36, 39, 883479) # UTC time in Naive
form.
>>>
>>> local_tz = pytz.timezone('Europe/Paris') #Our Local timezone, to
which we want to convert the UTC time.
>>>
>>> now_utc = pytz.utc.localize(now_utc) #Add Timezone information to
UTC time.
>>>
>>> now_utc
datetime.datetime(2011, 5, 9, 6, 36, 39, 883479, tzinfo=<UTC>) # The
full datetime tuple
>>>
>>> local_time = now_utc.astimezone(local\_tz) # Convert to local
time.
>>>
>>> local_time #Current local time in Paris
datetime.datetime(2011, 5, 9, 8, 36, 39, 883479, tzinfo=<DstTzInfo
'Europe/Paris' CEST+2:00:00 DST>)

Here is one way, using the pytz module:
import pytz
utc_datetime = (datetime.datetime(1970, 1, 1, tzinfo=pytz.utc)
+ datetime.timedelta(seconds=seconds_since_epoch)
If you don't want to install the pytz module, you can copy the example UTC class from the datetime documentation (search for "class UTC"):
https://docs.python.org/2/library/datetime.html#tzinfo-objects

Here's stdlib only solution without 3-party modules.
.., this datetime is a UTC datetime. But when i pull it from the DB, it is unaware of the timezone. What i need to do, is convert this datetime to a "seconds from epoch" time for another function.emphasize is mine
To convert an unaware (naive) datetime object that represents time in UTC to POSIX timestamp:
from datetime import datetime
timestamp = (dt_from_db - datetime(1970, 1, 1)).total_seconds()
Example:
>>> from datetime import datetime
>>> dt = datetime.strptime('2013-06-01 01:06:18', '%Y-%m-%d %H:%M:%S')
>>> (dt - datetime(1970, 1, 1)).total_seconds()
1370048778.0
See Converting datetime.date to UTC timestamp in Python that provides solutions for various Python versions.
To answer the question from the title: In general you need pytz library to handle timezones in Python. In particular, you should use .localize method to convert an unaware datetime object into timezone-aware one.
import pytz # $ pip install pytz
from tzlocal import get_localzone # $ pip install tzlocal
tz = get_localzone() # local timezone whatever it is (just an example)
aware_dt = tz.localize(naive_dt_in_local_timezone, is_dst=None)
is_dst=None asserts that naive_dt_in_local_timezone exists and unambiguous.
Though you don't need it for UTC timezone because it always has the same UTC offset (zero) around the year and in all past years:
import pytz
aware_dt = utc_dt.replace(tzinfo=pytz.utc)
See Python - simplest and most coherent way to get timezone-aware current time in UTC? (it provides a stdlib-only solution):
aware_dt = utc_dt.replace(tzinfo=timezone.utc)

How can I convert HH:MM:SS string to UNIX epoch time?

I have a program (sar command line utility) which outputs it's lines with time column. I parse this file with my python script and I would like to convert sar's 02:31:33 PM into epochs e.g. 1377181906 (current year, month and day with hours, minutes and seconds from abovementioned string). How can this done in a less cumbersome way? I tried to do this by myself, but stuck with time/datetime and herd of their methods.

Here's one way to do it:
read the string into datetime using strptime
set year, month, day of the datetime object to current date's year, month and day via replace
convert datetime into unix timestamp via calendar.timegm
>>> from datetime import datetime
>>> import calendar
>>> dt = datetime.strptime("02:31:33 PM", "%I:%M:%S %p")
>>> dt_now = datetime.now()
>>> dt = dt.replace(year=dt_now.year, month=dt_now.month, day=dt_now.day)
>>> calendar.timegm(dt.utctimetuple())
1377138693
Note that in python >= 3.3, you can get the timestamp from a datetime by calling dt.timestamp().
Also see:
Python Create unix timestamp five minutes in the future

An another way to have epoch time is to use mktime from time module and pass time tuple of date, so you can do this:
>>> from datetime import datetime
>>> from time import mktime
>>> dt = datetime.strptime("02:31:33 PM", "%H:%M:%S %p")
>>> dt_now = datetime.now()
>>> dt = dt.replace(year=dt_now.year, month=dt_now.month, day=dt_now.day)
>>> int(mktime(dt.timetuple()))
1377131493

Converting unix timestamp string to readable date

I have a string representing a unix timestamp (i.e. "1284101485") in Python, and I'd like to convert it to a readable date. When I use time.strftime, I get a TypeError:
>>>import time
>>>print time.strftime("%B %d %Y", "1284101485")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: argument must be 9-item sequence, not str

Use datetime module:
from datetime import datetime
ts = int('1284101485')
# if you encounter a "year is out of range" error the timestamp
# may be in milliseconds, try `ts /= 1000` in that case
print(datetime.utcfromtimestamp(ts).strftime('%Y-%m-%d %H:%M:%S'))

>>> from datetime import datetime
>>> datetime.fromtimestamp(1172969203.1)
datetime.datetime(2007, 3, 4, 0, 46, 43, 100000)
Taken from http://seehuhn.de/pages/pdate

The most voted answer suggests using fromtimestamp which is error prone since it uses the local timezone. To avoid issues a better approach is to use UTC:
datetime.datetime.utcfromtimestamp(posix_time).strftime('%Y-%m-%dT%H:%M:%SZ')
Where posix_time is the Posix epoch time you want to convert

>>> import time
>>> time.ctime(int("1284101485"))
'Fri Sep 10 16:51:25 2010'
>>> time.strftime("%D %H:%M", time.localtime(int("1284101485")))
'09/10/10 16:51'

There are two parts:
Convert the unix timestamp ("seconds since epoch") to the local time
Display the local time in the desired format.
A portable way to get the local time that works even if the local time zone had a different utc offset in the past and python has no access to the tz database is to use a pytz timezone:
#!/usr/bin/env python
from datetime import datetime
import tzlocal # $ pip install tzlocal
unix_timestamp = float("1284101485")
local_timezone = tzlocal.get_localzone() # get pytz timezone
local_time = datetime.fromtimestamp(unix_timestamp, local_timezone)
To display it, you could use any time format that is supported by your system e.g.:
print(local_time.strftime("%Y-%m-%d %H:%M:%S.%f%z (%Z)"))
print(local_time.strftime("%B %d %Y")) # print date in your format
If you do not need a local time, to get a readable UTC time instead:
utc_time = datetime.utcfromtimestamp(unix_timestamp)
print(utc_time.strftime("%Y-%m-%d %H:%M:%S.%f+00:00 (UTC)"))
If you don't care about the timezone issues that might affect what date is returned or if python has access to the tz database on your system:
local_time = datetime.fromtimestamp(unix_timestamp)
print(local_time.strftime("%Y-%m-%d %H:%M:%S.%f"))
On Python 3, you could get a timezone-aware datetime using only stdlib (the UTC offset may be wrong if python has no access to the tz database on your system e.g., on Windows):
#!/usr/bin/env python3
from datetime import datetime, timezone
utc_time = datetime.fromtimestamp(unix_timestamp, timezone.utc)
local_time = utc_time.astimezone()
print(local_time.strftime("%Y-%m-%d %H:%M:%S.%f%z (%Z)"))
Functions from the time module are thin wrappers around the corresponding C API and therefore they may be less portable than the corresponding datetime methods otherwise you could use them too:
#!/usr/bin/env python
import time
unix_timestamp = int("1284101485")
utc_time = time.gmtime(unix_timestamp)
local_time = time.localtime(unix_timestamp)
print(time.strftime("%Y-%m-%d %H:%M:%S", local_time))
print(time.strftime("%Y-%m-%d %H:%M:%S+00:00 (UTC)", utc_time))

In Python 3.6+:
import datetime
timestamp = 1642445213
value = datetime.datetime.fromtimestamp(timestamp)
print(f"{value:%Y-%m-%d %H:%M:%S}")
Output (local time)
2022-01-17 20:46:53
Explanation
Line #1: Import datetime library.
Line #2: Unix time which is seconds since 1970-01-01.
Line #3: Converts this to a unix time object, check with: type(value)
Line #4: Prints in the same format as strp. Local time. To print in UTC see example below.
Bonus
To save the date to a string then print it, use this:
my_date = f"{value:%Y-%m-%d %H:%M:%S}"
print(my_date)
To output in UTC:
value = datetime.datetime.fromtimestamp(timestamp, tz=datetime.timezone.utc)
# 2022-01-17 18:50:52

Other than using time/datetime package, pandas can also be used to solve the same problem.Here is how we can use pandas to convert timestamp to readable date:
Timestamps can be in two formats:
13 digits(milliseconds) -
To convert milliseconds to date, use:
import pandas
result_ms=pandas.to_datetime('1493530261000',unit='ms')
str(result_ms)
Output: '2017-04-30 05:31:01'
10 digits(seconds) -
To convert seconds to date, use:
import pandas
result_s=pandas.to_datetime('1493530261',unit='s')
str(result_s)
Output: '2017-04-30 05:31:01'

For a human readable timestamp from a UNIX timestamp, I have used this in scripts before:
import os, datetime
datetime.datetime.fromtimestamp(float(os.path.getmtime("FILE"))).strftime("%B %d, %Y")
Output:
'December 26, 2012'

You can convert the current time like this
t=datetime.fromtimestamp(time.time())
t.strftime('%Y-%m-%d')
'2012-03-07'
To convert a date in string to different formats.
import datetime,time
def createDateObject(str_date,strFormat="%Y-%m-%d"):
timeStamp = time.mktime(time.strptime(str_date,strFormat))
return datetime.datetime.fromtimestamp(timeStamp)
def FormatDate(objectDate,strFormat="%Y-%m-%d"):
return objectDate.strftime(strFormat)
Usage
=====
o=createDateObject('2013-03-03')
print FormatDate(o,'%d-%m-%Y')
Output 03-03-2013

timestamp ="124542124"
value = datetime.datetime.fromtimestamp(timestamp)
exct_time = value.strftime('%d %B %Y %H:%M:%S')
Get the readable date from timestamp with time also, also you can change the format of the date.

Note that utcfromtimestamp can lead to unexpected results since it returns a naive datetime object. Python treats naive datetime as local time - while UNIX time refers to UTC.
This ambiguity can be avoided by setting the tz argument in fromtimestamp:
from datetime import datetime, timezone
dtobj = datetime.fromtimestamp(1284101485, timezone.utc)
>>> print(repr(dtobj))
datetime.datetime(2010, 9, 10, 6, 51, 25, tzinfo=datetime.timezone.utc)
Now you can format to string, e.g. an ISO8601 compliant format:
>>> print(dtobj.isoformat(timespec='milliseconds').replace('+00:00', 'Z'))
2010-09-10T06:51:25.000Z

Use the following codes, I hope it will solve your problem.
import datetime as dt
print(dt.datetime.fromtimestamp(int("1284101485")).strftime('%Y-%m-%d %H:%M:%S'))

Use datetime.strftime(format):
from datetime import datetime
unixtime = int('1284101485')
# Print with local time
print(datetime.fromtimestamp(unixtime).strftime('%Y-%m-%d %H:%M:%S'))
# Print with UTC time
print(datetime.utcfromtimestamp(unixtime).strftime('%Y-%m-%d %H:%M:%S'))
datetime.fromtimestamp(timestamp): Return the local date corresponding to the POSIX timestamp, such as is returned by time.time().
datetime.utcfromtimestamp(timestamp): Return the UTC datetime corresponding to the POSIX timestamp, with tzinfo None. (The resulting object is naive.)

import datetime
temp = datetime.datetime.fromtimestamp(1386181800).strftime('%Y-%m-%d %H:%M:%S')
print temp

Another way that this can be done using gmtime and format function;
from time import gmtime
print('{}-{}-{} {}:{}:{}'.format(*gmtime(1538654264.703337)))
Output: 2018-10-4 11:57:44

If you are working with a dataframe and do not want the series cannot be converted to class int error. Use the code below.
new_df= pd.to_datetime(df_new['time'], unit='s')

i just successfully used:
>>> type(tstamp)
pandas.tslib.Timestamp
>>> newDt = tstamp.date()
>>> type(newDt)
datetime.date

You can use easy_date to make it easy:
import date_converter
my_date_string = date_converter.timestamp_to_string(1284101485, "%B %d, %Y")

quick and dirty one liner:
'-'.join(str(x) for x in list(tuple(datetime.datetime.now().timetuple())[:6]))
'2013-5-5-1-9-43'