How do I convert a datetime string in local time to a string in UTC time?
I'm sure I've done this before, but can't find it and SO will hopefully help me (and others) do that in future.
Clarification: For example, if I have 2008-09-17 14:02:00 in my local timezone (+10), I'd like to generate a string with the equivalent UTC time: 2008-09-17 04:02:00.
Also, from http://lucumr.pocoo.org/2011/7/15/eppur-si-muove/, note that in general this isn't possible as with DST and other issues there is no unique conversion from local time to UTC time.
For getting around day-light saving, etc.
None of the above answers particularly helped me. The code below works for GMT.
def get_utc_from_local(date_time, local_tz=None):
assert date_time.__class__.__name__ == 'datetime'
if local_tz is None:
local_tz = pytz.timezone(settings.TIME_ZONE) # Django eg, "Europe/London"
local_time = local_tz.normalize(local_tz.localize(date_time))
return local_time.astimezone(pytz.utc)
import pytz
from datetime import datetime
summer_11_am = datetime(2011, 7, 1, 11)
get_utc_from_local(summer_11_am)
>>>datetime.datetime(2011, 7, 1, 10, 0, tzinfo=<UTC>)
winter_11_am = datetime(2011, 11, 11, 11)
get_utc_from_local(winter_11_am)
>>>datetime.datetime(2011, 11, 11, 11, 0, tzinfo=<UTC>)
I did it like this:
>>> utc_delta = datetime.utcnow()-datetime.now()
>>> utc_time = datetime(2008, 9, 17, 14, 2, 0) + utc_delta
>>> print(utc_time)
2008-09-17 19:01:59.999996
If you want to get fancy, you can turn this into a functor:
class to_utc():
utc_delta = datetime.utcnow() - datetime.now()
def __call__(cls, t):
return t + cls.utc_delta
Result:
>>> utc_converter = to_utc()
>>> print(utc_converter(datetime(2008, 9, 17, 14, 2, 0)))
2008-09-17 19:01:59.999996
if you prefer datetime.datetime:
dt = datetime.strptime("2008-09-17 14:04:00","%Y-%m-%d %H:%M:%S")
utc_struct_time = time.gmtime(time.mktime(dt.timetuple()))
utc_dt = datetime.fromtimestamp(time.mktime(utc_struct_time))
print dt.strftime("%Y-%m-%d %H:%M:%S")
If you already have a datetime object my_dt you can change it to UTC with:
datetime.datetime.utcfromtimestamp(my_dt.timestamp())
If you already have a datetime object my_dt you can change it to UTC with:
datetime.datetime.utcfromtimestamp(my_dt.timestamp())
First, parse the string into a naive datetime object. This is an instance of datetime.datetime with no attached timezone information. See its documentation.
Use the pytz module, which comes with a full list of time zones + UTC. Figure out what the local timezone is, construct a timezone object from it, and manipulate and attach it to the naive datetime.
Finally, use datetime.astimezone() method to convert the datetime to UTC.
Source code, using local timezone "America/Los_Angeles", for the string "2001-2-3 10:11:12":
from datetime import datetime
import pytz
local = pytz.timezone("America/Los_Angeles")
naive = datetime.strptime("2001-2-3 10:11:12", "%Y-%m-%d %H:%M:%S")
local_dt = local.localize(naive, is_dst=None)
utc_dt = local_dt.astimezone(pytz.utc)
From there, you can use the strftime() method to format the UTC datetime as needed:
utc_dt.strftime("%Y-%m-%d %H:%M:%S")
In python 3.9.0, after you've parsed your local time local_time into datetime.datetime object, just use local_time.astimezone(datetime.timezone.utc).
First, parse the string into a naive datetime object. This is an instance of datetime.datetime with no attached timezone information. See its documentation.
Use the pytz module, which comes with a full list of time zones + UTC. Figure out what the local timezone is, construct a timezone object from it, and manipulate and attach it to the naive datetime.
Finally, use datetime.astimezone() method to convert the datetime to UTC.
Source code, using local timezone "America/Los_Angeles", for the string "2001-2-3 10:11:12":
from datetime import datetime
import pytz
local = pytz.timezone("America/Los_Angeles")
naive = datetime.strptime("2001-2-3 10:11:12", "%Y-%m-%d %H:%M:%S")
local_dt = local.localize(naive, is_dst=None)
utc_dt = local_dt.astimezone(pytz.utc)
From there, you can use the strftime() method to format the UTC datetime as needed:
utc_dt.strftime("%Y-%m-%d %H:%M:%S")
I did it like this:
>>> utc_delta = datetime.utcnow()-datetime.now()
>>> utc_time = datetime(2008, 9, 17, 14, 2, 0) + utc_delta
>>> print(utc_time)
2008-09-17 19:01:59.999996
If you want to get fancy, you can turn this into a functor:
class to_utc():
utc_delta = datetime.utcnow() - datetime.now()
def __call__(cls, t):
return t + cls.utc_delta
Result:
>>> utc_converter = to_utc()
>>> print(utc_converter(datetime(2008, 9, 17, 14, 2, 0)))
2008-09-17 19:01:59.999996
First, parse the string into a naive datetime object. This is an instance of datetime.datetime with no attached timezone information. See its documentation.
Use the pytz module, which comes with a full list of time zones + UTC. Figure out what the local timezone is, construct a timezone object from it, and manipulate and attach it to the naive datetime.
Finally, use datetime.astimezone() method to convert the datetime to UTC.
Source code, using local timezone "America/Los_Angeles", for the string "2001-2-3 10:11:12":
from datetime import datetime
import pytz
local = pytz.timezone("America/Los_Angeles")
naive = datetime.strptime("2001-2-3 10:11:12", "%Y-%m-%d %H:%M:%S")
local_dt = local.localize(naive, is_dst=None)
utc_dt = local_dt.astimezone(pytz.utc)
From there, you can use the strftime() method to format the UTC datetime as needed:
utc_dt.strftime("%Y-%m-%d %H:%M:%S")
How about -
time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime(seconds))
if seconds is None then it converts the local time to UTC time else converts the passed in time to UTC.
NOTE -- As of 2020 you should not be using .utcnow() or .utcfromtimestamp(xxx). As you've presumably moved on to python3,you should be using timezone aware datetime objects.
>>> from datetime import timezone
>>> dt_now = datetime.now(tz=timezone.utc)
>>> dt_ts = datetime.fromtimestamp(1571595618.0, tz=timezone.utc)
for details see: see: https://blog.ganssle.io/articles/2019/11/utcnow.html
The datetime module's utcnow() function can be used to obtain the current UTC time.
>>> import datetime
>>> utc_datetime = datetime.datetime.utcnow()
>>> utc_datetime.strftime("%Y-%m-%d %H:%M:%S")
'2010-02-01 06:59:19'
As the link mentioned above by Tom: http://lucumr.pocoo.org/2011/7/15/eppur-si-muove/ says:
UTC is a timezone without daylight saving time and still a timezone without configuration changes in the past.
Always measure and store time in UTC.
If you need to record where the time was taken, store that separately. Do not store the local time + timezone information!
NOTE - If any of your data is in a region that uses DST, use pytz and take a look at John Millikin's answer.
If you want to obtain the UTC time from a given string and your lucky enough to be in a region in the world that either doesn't use DST, or you have data that is only offset from UTC without DST applied:
--> using local time as the basis for the offset value:
>>> # Obtain the UTC Offset for the current system:
>>> UTC_OFFSET_TIMEDELTA = datetime.datetime.utcnow() - datetime.datetime.now()
>>> local_datetime = datetime.datetime.strptime("2008-09-17 14:04:00", "%Y-%m-%d %H:%M:%S")
>>> result_utc_datetime = local_datetime + UTC_OFFSET_TIMEDELTA
>>> result_utc_datetime.strftime("%Y-%m-%d %H:%M:%S")
'2008-09-17 04:04:00'
--> Or, from a known offset, using datetime.timedelta():
>>> UTC_OFFSET = 10
>>> result_utc_datetime = local_datetime - datetime.timedelta(hours=UTC_OFFSET)
>>> result_utc_datetime.strftime("%Y-%m-%d %H:%M:%S")
'2008-09-17 04:04:00'
UPDATE:
Since python 3.2 datetime.timezone is available. You can generate a timezone aware datetime object with the command below:
import datetime
timezone_aware_dt = datetime.datetime.now(datetime.timezone.utc)
If your ready to take on timezone conversions go read this:
In python3:
pip install python-dateutil
from dateutil.parser import tz
mydt.astimezone(tz.gettz('UTC')).replace(tzinfo=None)
def local_to_utc(t):
secs = time.mktime(t)
return time.gmtime(secs)
def utc_to_local(t):
secs = calendar.timegm(t)
return time.localtime(secs)
Source: http://feihonghsu.blogspot.com/2008/02/converting-from-local-time-to-utc.html
Example usage from bd808: If your source is a datetime.datetime object t, call as:
local_to_utc(t.timetuple())
I found the best answer on another question here. It only uses python built-in libraries and does not require you to input your local timezone (a requirement in my case)
import time
import calendar
local_time = time.strptime("2018-12-13T09:32:00.000", "%Y-%m-%dT%H:%M:%S.%f")
local_seconds = time.mktime(local_time)
utc_time = time.gmtime(local_seconds)
I'm reposting the answer here since this question pops up in google instead of the linked question depending on the search keywords.
How about -
time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime(seconds))
if seconds is None then it converts the local time to UTC time else converts the passed in time to UTC.
I've had the most success with python-dateutil:
from dateutil import tz
def datetime_to_utc(date):
"""Returns date in UTC w/o tzinfo"""
return date.astimezone(tz.gettz('UTC')).replace(tzinfo=None) if date.tzinfo else date
For getting around day-light saving, etc.
None of the above answers particularly helped me. The code below works for GMT.
def get_utc_from_local(date_time, local_tz=None):
assert date_time.__class__.__name__ == 'datetime'
if local_tz is None:
local_tz = pytz.timezone(settings.TIME_ZONE) # Django eg, "Europe/London"
local_time = local_tz.normalize(local_tz.localize(date_time))
return local_time.astimezone(pytz.utc)
import pytz
from datetime import datetime
summer_11_am = datetime(2011, 7, 1, 11)
get_utc_from_local(summer_11_am)
>>>datetime.datetime(2011, 7, 1, 10, 0, tzinfo=<UTC>)
winter_11_am = datetime(2011, 11, 11, 11)
get_utc_from_local(winter_11_am)
>>>datetime.datetime(2011, 11, 11, 11, 0, tzinfo=<UTC>)
First, parse the string into a naive datetime object. This is an instance of datetime.datetime with no attached timezone information. See its documentation.
Use the pytz module, which comes with a full list of time zones + UTC. Figure out what the local timezone is, construct a timezone object from it, and manipulate and attach it to the naive datetime.
Finally, use datetime.astimezone() method to convert the datetime to UTC.
Source code, using local timezone "America/Los_Angeles", for the string "2001-2-3 10:11:12":
from datetime import datetime
import pytz
local = pytz.timezone("America/Los_Angeles")
naive = datetime.strptime("2001-2-3 10:11:12", "%Y-%m-%d %H:%M:%S")
local_dt = local.localize(naive, is_dst=None)
utc_dt = local_dt.astimezone(pytz.utc)
From there, you can use the strftime() method to format the UTC datetime as needed:
utc_dt.strftime("%Y-%m-%d %H:%M:%S")
Briefly, to convert any datetime date to UTC time:
from datetime import datetime
def to_utc(date):
return datetime(*date.utctimetuple()[:6])
Let's explain with an example. First, we need to create a datetime from the string:
>>> date = datetime.strptime("11 Feb 2011 17:33:54 -0800", "%d %b %Y %H:%M:%S %z")
Then, we can call the function:
>>> to_utc(date)
datetime.datetime(2011, 2, 12, 1, 33, 54)
Step by step how the function works:
>>> date.utctimetuple()
time.struct_time(tm_year=2011, tm_mon=2, tm_mday=12, tm_hour=1, tm_min=33, tm_sec=54, tm_wday=5, tm_yday=43, tm_isdst=0)
>>> date.utctimetuple()[:6]
(2011, 2, 12, 1, 33, 54)
>>> datetime(*date.utctimetuple()[:6])
datetime.datetime(2011, 2, 12, 1, 33, 54)
I have this code in one of my projects:
from datetime import datetime
## datetime.timezone works in newer versions of python
try:
from datetime import timezone
utc_tz = timezone.utc
except:
import pytz
utc_tz = pytz.utc
def _to_utc_date_string(ts):
# type (Union[date,datetime]]) -> str
"""coerce datetimes to UTC (assume localtime if nothing is given)"""
if (isinstance(ts, datetime)):
try:
## in python 3.6 and higher, ts.astimezone() will assume a
## naive timestamp is localtime (and so do we)
ts = ts.astimezone(utc_tz)
except:
## in python 2.7 and 3.5, ts.astimezone() will fail on
## naive timestamps, but we'd like to assume they are
## localtime
import tzlocal
ts = tzlocal.get_localzone().localize(ts).astimezone(utc_tz)
return ts.strftime("%Y%m%dT%H%M%SZ")
In python 3.9.0, after you've parsed your local time local_time into datetime.datetime object, just use local_time.astimezone(datetime.timezone.utc).
I'm having good luck with dateutil (which is widely recommended on SO for other related questions):
from datetime import *
from dateutil import *
from dateutil.tz import *
# METHOD 1: Hardcode zones:
utc_zone = tz.gettz('UTC')
local_zone = tz.gettz('America/Chicago')
# METHOD 2: Auto-detect zones:
utc_zone = tz.tzutc()
local_zone = tz.tzlocal()
# Convert time string to datetime
local_time = datetime.strptime("2008-09-17 14:02:00", '%Y-%m-%d %H:%M:%S')
# Tell the datetime object that it's in local time zone since
# datetime objects are 'naive' by default
local_time = local_time.replace(tzinfo=local_zone)
# Convert time to UTC
utc_time = local_time.astimezone(utc_zone)
# Generate UTC time string
utc_string = utc_time.strftime('%Y-%m-%d %H:%M:%S')
(Code was derived from this answer to Convert UTC datetime string to local datetime)
import time
import datetime
def Local2UTC(LocalTime):
EpochSecond = time.mktime(LocalTime.timetuple())
utcTime = datetime.datetime.utcfromtimestamp(EpochSecond)
return utcTime
>>> LocalTime = datetime.datetime.now()
>>> UTCTime = Local2UTC(LocalTime)
>>> LocalTime.ctime()
'Thu Feb 3 22:33:46 2011'
>>> UTCTime.ctime()
'Fri Feb 4 05:33:46 2011'
Here's a summary of common Python time conversions.
Some methods drop fractions of seconds, and are marked with (s). An explicit formula such as ts = (d - epoch) / unit can be used instead (thanks jfs).
calendar.timegm(struct_time)calendar.timegm(stz.localize(dt, is_dst=None).utctimetuple())calendar.timegm(dt.utctimetuple())calendar.timegm(dt.utctimetuple())time.gmtime(t)stz.localize(dt, is_dst=None).utctimetuple()dt.utctimetuple()dt.utctimetuple()datetime.fromtimestamp(t, None)datetime.datetime(struct_time[:6], tzinfo=UTC).astimezone(tz).replace(tzinfo=None)dt.replace(tzinfo=UTC).astimezone(tz).replace(tzinfo=None)dt.astimezone(tz).replace(tzinfo=None)datetime.utcfromtimestamp(t)datetime.datetime(*struct_time[:6])stz.localize(dt, is_dst=None).astimezone(UTC).replace(tzinfo=None)dt.astimezone(UTC).replace(tzinfo=None)datetime.fromtimestamp(t, tz)datetime.datetime(struct_time[:6], tzinfo=UTC).astimezone(tz)stz.localize(dt, is_dst=None)dt.replace(tzinfo=UTC)Source: taaviburns.ca
In python3:
pip install python-dateutil
from dateutil.parser import tz
mydt.astimezone(tz.gettz('UTC')).replace(tzinfo=None)
if you prefer datetime.datetime:
dt = datetime.strptime("2008-09-17 14:04:00","%Y-%m-%d %H:%M:%S")
utc_struct_time = time.gmtime(time.mktime(dt.timetuple()))
utc_dt = datetime.fromtimestamp(time.mktime(utc_struct_time))
print dt.strftime("%Y-%m-%d %H:%M:%S")
Briefly, to convert any datetime date to UTC time:
from datetime import datetime
def to_utc(date):
return datetime(*date.utctimetuple()[:6])
Let's explain with an example. First, we need to create a datetime from the string:
>>> date = datetime.strptime("11 Feb 2011 17:33:54 -0800", "%d %b %Y %H:%M:%S %z")
Then, we can call the function:
>>> to_utc(date)
datetime.datetime(2011, 2, 12, 1, 33, 54)
Step by step how the function works:
>>> date.utctimetuple()
time.struct_time(tm_year=2011, tm_mon=2, tm_mday=12, tm_hour=1, tm_min=33, tm_sec=54, tm_wday=5, tm_yday=43, tm_isdst=0)
>>> date.utctimetuple()[:6]
(2011, 2, 12, 1, 33, 54)
>>> datetime(*date.utctimetuple()[:6])
datetime.datetime(2011, 2, 12, 1, 33, 54)
You can do it with:
>>> from time import strftime, gmtime, localtime
>>> strftime('%H:%M:%S', gmtime()) #UTC time
>>> strftime('%H:%M:%S', localtime()) # localtime
One more example with pytz, but includes localize(), which saved my day.
import pytz, datetime
utc = pytz.utc
fmt = '%Y-%m-%d %H:%M:%S'
amsterdam = pytz.timezone('Europe/Amsterdam')
dt = datetime.datetime.strptime("2012-04-06 10:00:00", fmt)
am_dt = amsterdam.localize(dt)
print am_dt.astimezone(utc).strftime(fmt)
'2012-04-06 08:00:00'
I found the best answer on another question here. It only uses python built-in libraries and does not require you to input your local timezone (a requirement in my case)
import time
import calendar
local_time = time.strptime("2018-12-13T09:32:00.000", "%Y-%m-%dT%H:%M:%S.%f")
local_seconds = time.mktime(local_time)
utc_time = time.gmtime(local_seconds)
I'm reposting the answer here since this question pops up in google instead of the linked question depending on the search keywords.
One more example with pytz, but includes localize(), which saved my day.
import pytz, datetime
utc = pytz.utc
fmt = '%Y-%m-%d %H:%M:%S'
amsterdam = pytz.timezone('Europe/Amsterdam')
dt = datetime.datetime.strptime("2012-04-06 10:00:00", fmt)
am_dt = amsterdam.localize(dt)
print am_dt.astimezone(utc).strftime(fmt)
'2012-04-06 08:00:00'
def local_to_utc(t):
secs = time.mktime(t)
return time.gmtime(secs)
def utc_to_local(t):
secs = calendar.timegm(t)
return time.localtime(secs)
Source: http://feihonghsu.blogspot.com/2008/02/converting-from-local-time-to-utc.html
Example usage from bd808: If your source is a datetime.datetime object t, call as:
local_to_utc(t.timetuple())
This thread seems to be missing an option available since Python 3.6: datetime.astimezone(tz=None) can be used to get an aware datetime object representing local time (docs). This can then easily be converted to UTC.
from datetime import datetime, timezone
s = "2008-09-17 14:02:00"
# to datetime object:
dt = datetime.fromisoformat(s) # Python 3.7
# I'm on time zone Europe/Berlin; CEST/UTC+2 during summer 2008
dt = dt.astimezone()
print(dt)
# 2008-09-17 14:02:00+02:00
# ...and to UTC:
dtutc = dt.astimezone(timezone.utc)
print(dtutc)
# 2008-09-17 12:02:00+00:00
There is one caveat though, see astimezone(None) gives aware datetime, unaware of DST.
Here's a summary of common Python time conversions.
Some methods drop fractions of seconds, and are marked with (s). An explicit formula such as ts = (d - epoch) / unit can be used instead (thanks jfs).
calendar.timegm(struct_time)calendar.timegm(stz.localize(dt, is_dst=None).utctimetuple())calendar.timegm(dt.utctimetuple())calendar.timegm(dt.utctimetuple())time.gmtime(t)stz.localize(dt, is_dst=None).utctimetuple()dt.utctimetuple()dt.utctimetuple()datetime.fromtimestamp(t, None)datetime.datetime(struct_time[:6], tzinfo=UTC).astimezone(tz).replace(tzinfo=None)dt.replace(tzinfo=UTC).astimezone(tz).replace(tzinfo=None)dt.astimezone(tz).replace(tzinfo=None)datetime.utcfromtimestamp(t)datetime.datetime(*struct_time[:6])stz.localize(dt, is_dst=None).astimezone(UTC).replace(tzinfo=None)dt.astimezone(UTC).replace(tzinfo=None)datetime.fromtimestamp(t, tz)datetime.datetime(struct_time[:6], tzinfo=UTC).astimezone(tz)stz.localize(dt, is_dst=None)dt.replace(tzinfo=UTC)Source: taaviburns.ca
def local_to_utc(t):
secs = time.mktime(t)
return time.gmtime(secs)
def utc_to_local(t):
secs = calendar.timegm(t)
return time.localtime(secs)
Source: http://feihonghsu.blogspot.com/2008/02/converting-from-local-time-to-utc.html
Example usage from bd808: If your source is a datetime.datetime object t, call as:
local_to_utc(t.timetuple())
How about -
time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime(seconds))
if seconds is None then it converts the local time to UTC time else converts the passed in time to UTC.
I've had the most success with python-dateutil:
from dateutil import tz
def datetime_to_utc(date):
"""Returns date in UTC w/o tzinfo"""
return date.astimezone(tz.gettz('UTC')).replace(tzinfo=None) if date.tzinfo else date
Using http://crsmithdev.com/arrow/
arrowObj = arrow.Arrow.strptime('2017-02-20 10:00:00', '%Y-%m-%d %H:%M:%S' , 'US/Eastern')
arrowObj.to('UTC') or arrowObj.to('local')
This library makes life easy :)
import time
import datetime
def Local2UTC(LocalTime):
EpochSecond = time.mktime(LocalTime.timetuple())
utcTime = datetime.datetime.utcfromtimestamp(EpochSecond)
return utcTime
>>> LocalTime = datetime.datetime.now()
>>> UTCTime = Local2UTC(LocalTime)
>>> LocalTime.ctime()
'Thu Feb 3 22:33:46 2011'
>>> UTCTime.ctime()
'Fri Feb 4 05:33:46 2011'
You can do it with:
>>> from time import strftime, gmtime, localtime
>>> strftime('%H:%M:%S', gmtime()) #UTC time
>>> strftime('%H:%M:%S', localtime()) # localtime
def local_to_utc(t):
secs = time.mktime(t)
return time.gmtime(secs)
def utc_to_local(t):
secs = calendar.timegm(t)
return time.localtime(secs)
Source: http://feihonghsu.blogspot.com/2008/02/converting-from-local-time-to-utc.html
Example usage from bd808: If your source is a datetime.datetime object t, call as:
local_to_utc(t.timetuple())
I'm having good luck with dateutil (which is widely recommended on SO for other related questions):
from datetime import *
from dateutil import *
from dateutil.tz import *
# METHOD 1: Hardcode zones:
utc_zone = tz.gettz('UTC')
local_zone = tz.gettz('America/Chicago')
# METHOD 2: Auto-detect zones:
utc_zone = tz.tzutc()
local_zone = tz.tzlocal()
# Convert time string to datetime
local_time = datetime.strptime("2008-09-17 14:02:00", '%Y-%m-%d %H:%M:%S')
# Tell the datetime object that it's in local time zone since
# datetime objects are 'naive' by default
local_time = local_time.replace(tzinfo=local_zone)
# Convert time to UTC
utc_time = local_time.astimezone(utc_zone)
# Generate UTC time string
utc_string = utc_time.strftime('%Y-%m-%d %H:%M:%S')
(Code was derived from this answer to Convert UTC datetime string to local datetime)
This thread seems to be missing an option available since Python 3.6: datetime.astimezone(tz=None) can be used to get an aware datetime object representing local time (docs). This can then easily be converted to UTC.
from datetime import datetime, timezone
s = "2008-09-17 14:02:00"
# to datetime object:
dt = datetime.fromisoformat(s) # Python 3.7
# I'm on time zone Europe/Berlin; CEST/UTC+2 during summer 2008
dt = dt.astimezone()
print(dt)
# 2008-09-17 14:02:00+02:00
# ...and to UTC:
dtutc = dt.astimezone(timezone.utc)
print(dtutc)
# 2008-09-17 12:02:00+00:00
There is one caveat though, see astimezone(None) gives aware datetime, unaware of DST.
NOTE -- As of 2020 you should not be using .utcnow() or .utcfromtimestamp(xxx). As you've presumably moved on to python3,you should be using timezone aware datetime objects.
>>> from datetime import timezone
>>> dt_now = datetime.now(tz=timezone.utc)
>>> dt_ts = datetime.fromtimestamp(1571595618.0, tz=timezone.utc)
for details see: see: https://blog.ganssle.io/articles/2019/11/utcnow.html
The datetime module's utcnow() function can be used to obtain the current UTC time.
>>> import datetime
>>> utc_datetime = datetime.datetime.utcnow()
>>> utc_datetime.strftime("%Y-%m-%d %H:%M:%S")
'2010-02-01 06:59:19'
As the link mentioned above by Tom: http://lucumr.pocoo.org/2011/7/15/eppur-si-muove/ says:
UTC is a timezone without daylight saving time and still a timezone without configuration changes in the past.
Always measure and store time in UTC.
If you need to record where the time was taken, store that separately. Do not store the local time + timezone information!
NOTE - If any of your data is in a region that uses DST, use pytz and take a look at John Millikin's answer.
If you want to obtain the UTC time from a given string and your lucky enough to be in a region in the world that either doesn't use DST, or you have data that is only offset from UTC without DST applied:
--> using local time as the basis for the offset value:
>>> # Obtain the UTC Offset for the current system:
>>> UTC_OFFSET_TIMEDELTA = datetime.datetime.utcnow() - datetime.datetime.now()
>>> local_datetime = datetime.datetime.strptime("2008-09-17 14:04:00", "%Y-%m-%d %H:%M:%S")
>>> result_utc_datetime = local_datetime + UTC_OFFSET_TIMEDELTA
>>> result_utc_datetime.strftime("%Y-%m-%d %H:%M:%S")
'2008-09-17 04:04:00'
--> Or, from a known offset, using datetime.timedelta():
>>> UTC_OFFSET = 10
>>> result_utc_datetime = local_datetime - datetime.timedelta(hours=UTC_OFFSET)
>>> result_utc_datetime.strftime("%Y-%m-%d %H:%M:%S")
'2008-09-17 04:04:00'
UPDATE:
Since python 3.2 datetime.timezone is available. You can generate a timezone aware datetime object with the command below:
import datetime
timezone_aware_dt = datetime.datetime.now(datetime.timezone.utc)
If your ready to take on timezone conversions go read this:
Using http://crsmithdev.com/arrow/
arrowObj = arrow.Arrow.strptime('2017-02-20 10:00:00', '%Y-%m-%d %H:%M:%S' , 'US/Eastern')
arrowObj.to('UTC') or arrowObj.to('local')
This library makes life easy :)
Source: Stackoverflow.com