Convert datetime to Unix timestamp and convert it back in python

Rather than this expression to create a POSIX timestamp from dt,

(dt - datetime(1970,1,1)).total_seconds()

Use this:

int(dt.strftime("%s"))

I get the right answer in your example using the second method.

EDIT: Some followup… After some comments (see below), I was curious about the lack of support or documentation for %s in strftime. Here’s what I found:

In the Python source for datetime and time, the string STRFTIME_FORMAT_CODES tells us:

"Other codes may be available on your platform.
 See documentation for the C library strftime function."

So now if we man strftime (on BSD systems such as Mac OS X), you’ll find support for %s:

"%s is replaced by the number of seconds since the Epoch, UTC (see mktime(3))."

Anyways, that’s why %s works on the systems it does. But there are better solutions to OP’s problem (that take timezones into account). See @abarnert’s accepted answer here.

Well, when converting TO unix timestamp, python is basically assuming UTC, but while converting back it will give you a date converted to your local timezone.

See this question/answer;
Get timezone used by datetime.datetime.fromtimestamp()

solution is

import time
import datetime
d = datetime.date(2015,1,5)

unixtime = time.mktime(d.timetuple())

If you want to convert a python datetime to seconds since epoch you should do it explicitly:

>>> import datetime
>>> datetime.datetime(2012, 04, 01, 0, 0).strftime('%s')
'1333234800'
>>> (datetime.datetime(2012, 04, 01, 0, 0) - datetime.datetime(1970, 1, 1)).total_seconds()
1333238400.0

In Python 3.3+ you can use timestamp() instead:

>>> import datetime
>>> datetime.datetime(2012, 4, 1, 0, 0).timestamp()
1333234800.0

You’ve missed the time zone info (already answered, agreed)

arrow package allows to avoid this torture with datetimes; It is already written, tested, pypi-published, cross-python (2.6 — 3.xx).

All you need: pip install arrow (or add to dependencies)

Solution for your case

dt = datetime(2013,9,1,11)
arrow.get(dt).timestamp
# >>> 1378033200

bc = arrow.get(1378033200).datetime
print(bc)
# >>> datetime.datetime(2013, 9, 1, 11, 0, tzinfo=tzutc())
print(bc.isoformat())
# >>> '2013-09-01T11:00:00+00:00'

If your datetime object represents UTC time, don’t use time.mktime, as it assumes the tuple is in your local timezone. Instead, use calendar.timegm:

>>> import datetime, calendar
>>> d = datetime.datetime(1970, 1, 1, 0, 1, 0)
>>> calendar.timegm(d.timetuple())
60

def dt2ts(dt, utc=False):
    if utc:
        return calendar.timegm(dt.timetuple())
    if dt.tzinfo is None:
        return int(time.mktime(dt.timetuple()))
    utc_dt = dt.astimezone(tz.tzutc()).timetuple()
    return calendar.timegm(utc_dt)

If you want UTC timestamp :time.mktime just for local dt .Use calendar.timegm is safe but dt must the utc zone so change the zone to utc. If dt in UTC just use calendar.timegm.

For working with UTC timezones:

time_stamp = calendar.timegm(dt.timetuple())

datetime.utcfromtimestamp(time_stamp)

def datetime_to_epoch(d1):
"""
January 1st, 1970 at 00:00:00 UTC is referred to as the Unix epoch
:param d1: input date
:return: seconds since unix epoch
"""
if not d1.tzinfo:
    raise ValueError("date is missing timezone information")

d2 = datetime(1970, 1, 1, tzinfo=timezone.utc)
time_delta = d1 - d2
ts = int(time_delta.total_seconds())
return ts


def epoch_to_datetime_string(timestamp, tz_name="UTC", **kwargs):
"""
method to convert unix timestamp to date time string
:param ts: 10 digit unix timestamp in seconds
:param tz_name: timezone name
:param kwargs: formatter=<formatter-string>
:return: date time string in timezone
"""

naive_date = datetime.fromtimestamp(timestamp)
aware_date = naive_date.astimezone(pytz.timezone(tz_name))
formatter = kwargs.pop("formatter", "%d %b %Y %H:%M:%S")
return aware_date.strftime(formatter)

This class will cover your needs, you can pass the variable into ConvertUnixToDatetime & call which function you want it to operate based off.

from datetime import datetime
import time

class ConvertUnixToDatetime:
    def __init__(self, date):
        self.date = date

    # Convert unix to date object
    def convert_unix(self):
        unix = self.date

        # Check if unix is a string or int & proceeds with correct conversion
        if type(unix).__name__ == 'str':
            unix = int(unix[0:10])
        else:
            unix = int(str(unix)[0:10])

        date = datetime.utcfromtimestamp(unix).strftime('%Y-%m-%d %H:%M:%S')

        return date

    # Convert date to unix object
    def convert_date(self):
        date = self.date

        # Check if datetime object or raise ValueError
        if type(date).__name__ == 'datetime':
            unixtime = int(time.mktime(date.timetuple()))
        else:
            raise ValueError('You are trying to pass a None Datetime object')
        return type(unixtime).__name__, unixtime


if __name__ == '__main__':

    # Test Date
    date_test = ConvertUnixToDatetime(datetime.today())
    date_test = date_test.convert_date()
    print(date_test)

    # Test Unix
    unix_test = ConvertUnixToDatetime(date_test[1])
    print(unix_test.convert_unix())

import time
from datetime import datetime
time.mktime(datetime.now().timetuple())