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I have two inputs time 00:00 and timezone 'Asia/Kolkata'
I want to convert this to UTC time like '18.30'
I don't want to add or subtract offsets because it may affect the day light saving
what i did is
local = pytz.timezone ("UTC")
nativetime = datetime.strptime (setTime,frmt)
local_dt = local.localize(nativetime, is_dst=None)
utc_dt = local_dt.astimezone(pytz.utc)
but this doesn't change anything, the time is not converted to UTC
Please help
Something like this, assuming you're on py3:
>>> import datetime
>>> import pytz
>>> tz = pytz.timezone('Asia/Kolkata')
>>> dt = datetime.datetime(2020, 8, 4, 0, 0, tzinfo=tz)
>>> dt.astimezone(pytz.utc)
datetime.datetime(2020, 8, 3, 18, 7, tzinfo=<UTC>)
>>>
Since you say you're new to Python, it might be good to skip pytz since it's going to be deprecated with Python 3.9. You can use dateutil instead, which can be replaced more easily with zoneinfo in Python 3.9.
from datetime import datetime, timezone
from dateutil.tz import gettz
# assuming you have something like
dt_naive = datetime.strptime('2020-08-05', '%Y-%m-%d')
# dt_naive has no time zone info, so set it:
dt_aware = dt_naive.replace(tzinfo=gettz('Asia/Kolkata'))
# now you can convert to another timezone using .astimezone:
dt_aware_utc = dt_aware.astimezone(timezone.utc)
# datetime.datetime(2020, 8, 4, 18, 30, tzinfo=datetime.timezone.utc)
# -> 5:30 hours behind, which matches dt_aware.utcoffset()
#thebjorn gave me the answer
here is what i did
def utc_to_local(utc_dt,local_tz):
local_dt = utc_dt.replace(tzinfo=pytz.utc).astimezone(local_tz)
return local_tz.normalize(local_dt)
setTime='00:00:00'
setZone='Asia/Kolkata'
datePart = str(datetime.utcnow()).split(' ')[0]
dateTimeUtcStr = datePart+' '+str(setTime)
tz = pytz.timezone('Asia/Kolkata')
tz_utc = pytz.timezone('UTC')
dateTimeRef = datetime.strptime(dateTimeUtcStr, '%Y-%m-%d %H:%M:%S')
#local to utc
tzUtc = pytz.timezone('UTC')
local_dt = tz.localize(dateTimeRef, is_dst=None)
utc_dt = local_dt.astimezone(pytz.utc)
print(utc_dt)
#utc to local
altTime = utc_to_local(utc_dt,tz)
print(altTime)
I'm trying to write a function that accepts a UTC timestamp (seconds since epoch) and emits a timezone-aware datetime for that timestamp with tz=utc. But I've encountered a strange issue.
Steps to reproduce:
(a) Set your system timezone to anything not-GMT. (In this case, Los Angeles. Also tested with various Russian, Chinese, South American and Icelandic timezones both before and after GMT+0000).
>>> import datetime
>>> from dateutil import tz
>>> epoch_seconds = 0
>>> dt = datetime.datetime.fromtimestamp(epoch_seconds)
>>> print(dt)
1969-12-31 16:00:00
>>> dt = dt.replace(tzinfo=tz.tzlocal())
>>> print(dt)
1969-12-31 16:00:00-08:00
>>> dt = dt.astimezone(tz=tz.tzutc())
>>> print(dt)
1970-01-01 00:00:00+00:00
>>> assert '{:%Y-%m-%d %H:%M:%S %z}'.format(dt) == '1970-01-01 00:00:00 +0000'
>>>
(b) Set your timezone to London/Dublin/something equivalent to GMT.
>>> import datetime
>>> from dateutil import tz
>>> epoch_seconds = 0
>>> dt = datetime.datetime.fromtimestamp(epoch_seconds)
>>> print(dt)
1970-01-01 01:00:00
>>> dt = dt.replace(tzinfo=tz.tzlocal())
>>> print(dt)
1970-01-01 01:00:00+00:00
>>> dt = dt.astimezone(tz=tz.tzutc())
>>> print(dt)
1970-01-01 01:00:00+00:00
>>> assert '{:%Y-%m-%d %H:%M:%S %z}'.format(dt) == '1970-01-01 00:00:00 +0000'
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AssertionError
>>>
Can you help me understand why this seemingly works in any non-GMT timezone but not in GMT?
The intent of the code is:
Create a datetime using 0 seconds since epoch: dt = datetime.datetime.fromtimestamp(0)
Tell that datetime what timezone it is currently in: dt = dt.replace(tzinfo=tz.tzlocal())
"Move" it from the local timezone to UTC: dt = dt.astimezone(tz=tz.tzutc())
I think the problem lies in dt = datetime.datetime.fromtimestamp(0) because even at that point calling print(dt) shows 01:00 as the time instead of 00:00.
Update It gives 1am because the UK was actually in "British Standard Time" (GMT+0100) on 1st January 1970. Maybe dateutil's tz doesn't know that? It's just an abstract representation of the current rules? Maybe?
I ended up solving this using the pytz library. I don't think it can be solved using datetime because datetime's timezone conversion doesn't know that the British used GMT+0100 for the entire of 1970 and not just for summer time.
With system timezone set to Europe/London:
>>> import datetime
>>> from pytz import timezone
>>> epoch_seconds = 0
>>> dt = datetime.datetime.utcfromtimestamp(epoch_seconds)
>>> print(dt)
1970-01-01 00:00:00
>>> dt = timezone('UTC').localize(dt)
>>> print(dt)
1970-01-01 00:00:00+00:00
>>> assert '{:%Y-%m-%d %H:%M:%S %z}'.format(dt) == '1970-01-01 00:00:00 +0000'
With system timezone set to America/Los_Angeles
>>> import datetime
>>> from pytz import timezone
>>> epoch_seconds = 0
>>> dt = datetime.datetime.utcfromtimestamp(epoch_seconds)
>>> print(dt)
1970-01-01 00:00:00
>>> dt = timezone('UTC').localize(dt)
>>> print(dt)
1970-01-01 00:00:00+00:00
>>> assert '{:%Y-%m-%d %H:%M:%S %z}'.format(dt) == '1970-01-01 00:00:00 +0000'
>>>
Local time never has to come into it this way - you can just generate a naïve timestamp, tell it to be UTC with pytz's localize.
I'm trying to write a function that accepts a UTC timestamp (seconds since epoch) and emits a timezone-aware datetime for that timestamp with tz=utc
#!/usr/bin/env python3
from datetime import datetime, timezone
aware_dt = datetime.fromtimestamp(epoch_seconds, timezone.utc)
I don't think it can be solved using datetime because datetime's timezone conversion doesn't know that the British used GMT+0100 for the entire of 1970 and not just for summer time.
If python has access to the tz database on your system then it does know the rules:
$ TZ=Europe/London ptpython
>>> from datetime import datetime, timezone
>>> epoch_seconds = 0
>>> aware_dt = datetime.fromtimestamp(epoch_seconds, timezone.utc)
>>> aware_dt
datetime.datetime(1970, 1, 1, 0, 0, tzinfo=datetime.timezone.utc)
>>> aware_dt.astimezone() # local time (1am)
datetime.datetime(1970, 1, 1, 1, 0, tzinfo=datetime.timezone(datetime.timedelta(0, 3600), 'BST'))
>>> _.astimezone(timezone.utc) # back to utc
datetime.datetime(1970, 1, 1, 0, 0, tzinfo=datetime.timezone.utc)
To provide a portable access to the tz database, you could use pytz timezone e.g., via tzlocal module:
>>> import tzlocal # $ pip install tzlocal
>>> datetime.fromtimestamp(epoch_seconds, tzlocal.get_localzone()) # local time (1am)
datetime.datetime(1970, 1, 1, 1, 0, tzinfo=<DstTzInfo 'Europe/London' BST+1:00:00 STD>)
btw, dateutil provides access to the tz database too. If it doesn't work: it is either the wrong usage or a bug. Try to update to the latest python-dateutil version, to see whether the issue disappears.
i have a list of datetimes in EU time zone:
[u'2014-11-01T09:00:00+01:00', u'2014-11-02T00:00:00+01:00', u'2014-11-03T00:00:00+01:00', u'2014-11-04T00:00:00+01:00', u'2014-11-05T00:00:00+01:00', u'2014-11-06T00:00:00+01:00', u'2014-11-07T00:00:00+01:00', u'2014-11-08T00:00:00+01:00', u'2014-11-09T00:00:00+01:00', u'2014-11-10T00:00:00+01:00', u'2014-11-11T00:00:00+01:00', u'2014-11-12T00:00:00+01:00', u'2014-11-13T00:00:00+01:00', u'2014-11-14T00:00:00+01:00', u'2014-11-15T00:00:00+01:00', u'2014-11-16T00:00:00+01:00', u'2014-11-17T00:00:00+01:00', u'2014-11-18T00:00:00+01:00', u'2014-11-19T00:00:00+01:00', u'2014-11-20T00:00:00+01:00', u'2014-11-21T00:00:00+01:00', u'2014-11-22T00:00:00+01:00', u'2014-11-23T00:00:00+01:00', u'2014-11-24T00:00:00+01:00', u'2014-11-25T00:00:00+01:00', u'2014-11-26T00:00:00+01:00', u'2014-11-27T00:00:00+01:00', u'2014-11-28T00:00:00+01:00', u'2014-11-29T00:00:00+01:00', u'2014-11-30T00:00:00+01:00', u'2014-12-01T00:00:00+01:00']
How do i convert each of them to PST time zone?
This should do it:
from pytz import timezone
import pytz
from dateutil.parser import parse
l = [u'2014-11-01T09:00:00+01:00', u'2014-11-02T00:00:00+01:00', u'2014-11-03T00:00:00+01:00', u'2014-11-04T00:00:00+01:00', u'2014-11-05T00:00:00+01:00', u'2014-11-06T00:00:00+01:00', u'2014-11-07T00:00:00+01:00', u'2014-11-08T00:00:00+01:00', u'2014-11-09T00:00:00+01:00', u'2014-11-10T00:00:00+01:00', u'2014-11-11T00:00:00+01:00', u'2014-11-12T00:00:00+01:00', u'2014-11-13T00:00:00+01:00', u'2014-11-14T00:00:00+01:00', u'2014-11-15T00:00:00+01:00', u'2014-11-16T00:00:00+01:00', u'2014-11-17T00:00:00+01:00', u'2014-11-18T00:00:00+01:00', u'2014-11-19T00:00:00+01:00', u'2014-11-20T00:00:00+01:00', u'2014-11-21T00:00:00+01:00', u'2014-11-22T00:00:00+01:00', u'2014-11-23T00:00:00+01:00', u'2014-11-24T00:00:00+01:00', u'2014-11-25T00:00:00+01:00', u'2014-11-26T00:00:00+01:00', u'2014-11-27T00:00:00+01:00', u'2014-11-28T00:00:00+01:00', u'2014-11-29T00:00:00+01:00', u'2014-11-30T00:00:00+01:00', u'2014-12-01T00:00:00+01:00']
amsterdam = timezone('Europe/Amsterdam')
pst = timezone('US/Pacific')
[parse(d).replace(tzinfo=amsterdam).astimezone(pst) for d in l]
There are two independent tasks:
parse rfc 3339 date/time format into an aware datetime object
>>> from dateutil.parser import parse
>>> aware_dt = parse('2014-11-01T09:00:00+01:00')
>>> aware_dt
datetime.datetime(2014, 11, 1, 9, 0, tzinfo=tzoffset(None, 3600))
convert it to America/Los_Angeles timezone
>>> import pytz
>>> tz = pytz.timezone('America/Los_Angeles')
>>> tz.normalize(aware_dt.astimezone(tz))
datetime.datetime(2014, 11, 1, 1, 0, tzinfo=<DstTzInfo 'America/Los_Angeles' PDT-1 day, 17:00:00 DST>)
import pytz,datetime
tz1 = pytz.timezone('Asia/Shanghai')
tz1
<DstTzInfo 'Asia/Shanghai' LMT+8:06:00 STD>
>>> str(tz1)
'Asia/Shanghai'
1.how can i get the string of LMT+8:06:00 from the output of tz1?
fmt = '%Y-%m-%d %H:%M:%S %Z%z'
dt1 = tz1.localize(datetime.datetime(2002, 10, 27, 6, 0, 0))
print(dt1.strftime(fmt))
2002-10-27 06:00:00 CST+0800
2.how can i get all the abbrevations of timezone which is composed of 3 upper character such as CST in 2002-10-27 06:00:00 CST+0800?
list(pytz.country_names) get all the abbrevations of country,list(pytz.all_timezones) get all the timezones.
list(pytz.all_timezones)
list(pytz.country_names)
1.how can i get the string of LMT+8:06:00 from the output of tz1?
A single pytz.timezone('Asia/Shanghai') object may correspond to several different tzinfo objects (different tzname(), dst(), and/or utcoffset()). The default representation of tz1 shows one of such objects. You need a concrete date to get the correct tzinfo:
>>> from datetime import datetime
>>> import pytz
>>> tz = pytz.timezone('Asia/Shanghai')
>>> tz
<DstTzInfo 'Asia/Shanghai' LMT+8:06:00 STD>
>>> fmt = '%Y-%m-%d %H:%M:%S %Z%z'
>>> tz.localize(datetime(2002, 10, 27, 6, 0, 0), is_dst=None).strftime(fmt)
'2002-10-27 06:00:00 CST+0800'
>>> tz.localize(datetime(1902, 10, 27, 6, 0, 0), is_dst=None).strftime(fmt)
'1902-10-27 06:00:00 LMT+0806'
i.e., Asia/Shanghai had +0806 utc offset in 1902.
2.how can i get all the abbrevations of timezone which is composed of 3 upper character such as CST in 2002-10-27 06:00:00 CST+0800?
If you have an aware datetime object then just call its .tzname() method or pass the date to the timezone explicitly:
>>> tz.tzname(datetime(2002, 10, 27, 6, 0, 0), is_dst=None)
'CST'
There is no public API to enumerate all possible tzname() values for a given zoneinfo timezone. You could use DstTzInfo._transition_info attribute, to get the value (without values from a far future (for obvious reasons)):
>>> datetime.now(tz).tzname()
'CST'
>>> {tzname for _, _, tzname in getattr(tz, '_transition_info', [])}
set(['CDT', 'CST', 'LMT'])
How do I convert a time to another timezone in Python?
I have found that the best approach is to convert the "moment" of interest to a utc-timezone-aware datetime object (in python, the timezone component is not required for datetime objects).
Then you can use astimezone to convert to the timezone of interest (reference).
from datetime import datetime
import pytz
utcmoment_naive = datetime.utcnow()
utcmoment = utcmoment_naive.replace(tzinfo=pytz.utc)
# print "utcmoment_naive: {0}".format(utcmoment_naive) # python 2
print("utcmoment_naive: {0}".format(utcmoment_naive))
print("utcmoment: {0}".format(utcmoment))
localFormat = "%Y-%m-%d %H:%M:%S"
timezones = ['America/Los_Angeles', 'Europe/Madrid', 'America/Puerto_Rico']
for tz in timezones:
localDatetime = utcmoment.astimezone(pytz.timezone(tz))
print(localDatetime.strftime(localFormat))
# utcmoment_naive: 2017-05-11 17:43:30.802644
# utcmoment: 2017-05-11 17:43:30.802644+00:00
# 2017-05-11 10:43:30
# 2017-05-11 19:43:30
# 2017-05-11 13:43:30
So, with the moment of interest in the local timezone (a time that exists), you convert it to utc like this (reference).
localmoment_naive = datetime.strptime('2013-09-06 14:05:10', localFormat)
localtimezone = pytz.timezone('Australia/Adelaide')
try:
localmoment = localtimezone.localize(localmoment_naive, is_dst=None)
print("Time exists")
utcmoment = localmoment.astimezone(pytz.utc)
except pytz.exceptions.NonExistentTimeError as e:
print("NonExistentTimeError")
Using pytz
from datetime import datetime
from pytz import timezone
fmt = "%Y-%m-%d %H:%M:%S %Z%z"
timezonelist = ['UTC','US/Pacific','Europe/Berlin']
for zone in timezonelist:
now_time = datetime.now(timezone(zone))
print now_time.strftime(fmt)
import datetime
import pytz
def convert_datetime_timezone(dt, tz1, tz2):
tz1 = pytz.timezone(tz1)
tz2 = pytz.timezone(tz2)
dt = datetime.datetime.strptime(dt,"%Y-%m-%d %H:%M:%S")
dt = tz1.localize(dt)
dt = dt.astimezone(tz2)
dt = dt.strftime("%Y-%m-%d %H:%M:%S")
return dt
-
dt: date time string
tz1: initial time zone
tz2: target time zone
-
> convert_datetime_timezone("2017-05-13 14:56:32", "Europe/Berlin", "PST8PDT")
'2017-05-13 05:56:32'
> convert_datetime_timezone("2017-05-13 14:56:32", "Europe/Berlin", "UTC")
'2017-05-13 12:56:32'
-
> pytz.all_timezones[0:10]
['Africa/Abidjan',
'Africa/Accra',
'Africa/Addis_Ababa',
'Africa/Algiers',
'Africa/Asmara',
'Africa/Asmera',
'Africa/Bamako',
'Africa/Bangui',
'Africa/Banjul',
'Africa/Bissau']
Python 3.9 adds the zoneinfo module so now only the the standard library is needed!
>>> from zoneinfo import ZoneInfo
>>> from datetime import datetime
>>> d = datetime(2020, 10, 31, 12, tzinfo=ZoneInfo('America/Los_Angeles'))
>>> d.astimezone(ZoneInfo('Europe/Berlin')) # 12:00 in Cali will be 20:00 in Berlin
datetime.datetime(2020, 10, 31, 20, 0, tzinfo=zoneinfo.ZoneInfo(key='Europe/Berlin'))
Wikipedia list of available time zones
Some functions such as now() and utcnow() return timezone-unaware datetimes, meaning they contain no timezone information. I recommend only requesting timezone-aware values from them using the keyword tz=ZoneInfo('localtime').
If astimezone gets a timezone-unaware input, it will assume it is local time, which can lead to errors:
>>> datetime.utcnow() # UTC -- NOT timezone-aware!!
datetime.datetime(2020, 6, 1, 22, 39, 57, 376479)
>>> datetime.now() # Local time -- NOT timezone-aware!!
datetime.datetime(2020, 6, 2, 0, 39, 57, 376675)
>>> datetime.now(tz=ZoneInfo('localtime')) # timezone-aware
datetime.datetime(2020, 6, 2, 0, 39, 57, 376806, tzinfo=zoneinfo.ZoneInfo(key='localtime'))
>>> datetime.now(tz=ZoneInfo('Europe/Berlin')) # timezone-aware
datetime.datetime(2020, 6, 2, 0, 39, 57, 376937, tzinfo=zoneinfo.ZoneInfo(key='Europe/Berlin'))
>>> datetime.utcnow().astimezone(ZoneInfo('Europe/Berlin')) # WRONG!!
datetime.datetime(2020, 6, 1, 22, 39, 57, 377562, tzinfo=zoneinfo.ZoneInfo(key='Europe/Berlin'))
Windows has no system time zone database, so here an extra package is needed:
pip install tzdata
There is a backport to allow use in Python 3.6 to 3.8:
sudo pip install backports.zoneinfo
Then:
from backports.zoneinfo import ZoneInfo
Time conversion
To convert a time in one timezone to another timezone in Python, you could use datetime.astimezone():
so, below code is to convert the local time to other time zone.
datetime.datetime.today() - return current the local time
datetime.astimezone() - convert the time zone, but we have to pass the time zone.
pytz.timezone('Asia/Kolkata') -passing the time zone to pytz module
Strftime - Convert Datetime to string
# Time conversion from local time
import datetime
import pytz
dt_today = datetime.datetime.today() # Local time
dt_India = dt_today.astimezone(pytz.timezone('Asia/Kolkata'))
dt_London = dt_today.astimezone(pytz.timezone('Europe/London'))
India = (dt_India.strftime('%m/%d/%Y %H:%M'))
London = (dt_London.strftime('%m/%d/%Y %H:%M'))
print("Indian standard time: "+India+" IST")
print("British Summer Time: "+London+" BST")
List all the time zones
import pytz
for tz in pytz.all_timezones:
print(tz)
To convert a time in one timezone to another timezone in Python, you could use datetime.astimezone():
time_in_new_timezone = time_in_old_timezone.astimezone(new_timezone)
Given aware_dt (a datetime object in some timezone), to convert it to other timezones and to print the times in a given time format:
#!/usr/bin/env python3
import pytz # $ pip install pytz
time_format = "%Y-%m-%d %H:%M:%S%z"
tzids = ['Asia/Shanghai', 'Europe/London', 'America/New_York']
for tz in map(pytz.timezone, tzids):
time_in_tz = aware_dt.astimezone(tz)
print(f"{time_in_tz:{time_format}}")
If f"" syntax is unavailable, you could replace it with "".format(**vars())
where you could set aware_dt from the current time in the local timezone:
from datetime import datetime
import tzlocal # $ pip install tzlocal
local_timezone = tzlocal.get_localzone()
aware_dt = datetime.now(local_timezone) # the current time
Or from the input time string in the local timezone:
naive_dt = datetime.strptime(time_string, time_format)
aware_dt = local_timezone.localize(naive_dt, is_dst=None)
where time_string could look like: '2016-11-19 02:21:42'. It corresponds to time_format = '%Y-%m-%d %H:%M:%S'.
is_dst=None forces an exception if the input time string corresponds to a non-existing or ambiguous local time such as during a DST transition. You could also pass is_dst=False, is_dst=True. See links with more details at Python: How do you convert datetime/timestamp from one timezone to another timezone?
For Python timezone conversions, I use the handy table from the PyCon 2012 presentation by Taavi Burns.
Please note: The first part of this answer is or version 1.x of pendulum. See below for a version 2.x answer.
I hope I'm not too late!
The pendulum library excels at this and other date-time calculations.
>>> import pendulum
>>> some_time_zones = ['Europe/Paris', 'Europe/Moscow', 'America/Toronto', 'UTC', 'Canada/Pacific', 'Asia/Macao']
>>> heres_a_time = '1996-03-25 12:03 -0400'
>>> pendulum_time = pendulum.datetime.strptime(heres_a_time, '%Y-%m-%d %H:%M %z')
>>> for tz in some_time_zones:
... tz, pendulum_time.astimezone(tz)
...
('Europe/Paris', <Pendulum [1996-03-25T17:03:00+01:00]>)
('Europe/Moscow', <Pendulum [1996-03-25T19:03:00+03:00]>)
('America/Toronto', <Pendulum [1996-03-25T11:03:00-05:00]>)
('UTC', <Pendulum [1996-03-25T16:03:00+00:00]>)
('Canada/Pacific', <Pendulum [1996-03-25T08:03:00-08:00]>)
('Asia/Macao', <Pendulum [1996-03-26T00:03:00+08:00]>)
Answer lists the names of the time zones that may be used with pendulum. (They're the same as for pytz.)
For version 2:
some_time_zones is a list of the names of the time zones that might be used in a program
heres_a_time is a sample time, complete with a time zone in the form '-0400'
I begin by converting the time to a pendulum time for subsequent processing
now I can show what this time is in each of the time zones in show_time_zones
...
>>> import pendulum
>>> some_time_zones = ['Europe/Paris', 'Europe/Moscow', 'America/Toronto', 'UTC', 'Canada/Pacific', 'Asia/Macao']
>>> heres_a_time = '1996-03-25 12:03 -0400'
>>> pendulum_time = pendulum.from_format('1996-03-25 12:03 -0400', 'YYYY-MM-DD hh:mm ZZ')
>>> for tz in some_time_zones:
... tz, pendulum_time.in_tz(tz)
...
('Europe/Paris', DateTime(1996, 3, 25, 17, 3, 0, tzinfo=Timezone('Europe/Paris')))
('Europe/Moscow', DateTime(1996, 3, 25, 19, 3, 0, tzinfo=Timezone('Europe/Moscow')))
('America/Toronto', DateTime(1996, 3, 25, 11, 3, 0, tzinfo=Timezone('America/Toronto')))
('UTC', DateTime(1996, 3, 25, 16, 3, 0, tzinfo=Timezone('UTC')))
('Canada/Pacific', DateTime(1996, 3, 25, 8, 3, 0, tzinfo=Timezone('Canada/Pacific')))
('Asia/Macao', DateTime(1996, 3, 26, 0, 3, 0, tzinfo=Timezone('Asia/Macao')))
For Python 3.2+ simple-date is a wrapper around pytz that tries to simplify things.
If you have a time then
SimpleDate(time).convert(tz="...")
may do what you want. But timezones are quite complex things, so it can get significantly more complicated - see the the docs.
# Program
import time
import os
os.environ['TZ'] = 'US/Eastern'
time.tzset()
print('US/Eastern in string form:',time.asctime())
os.environ['TZ'] = 'Australia/Melbourne'
time.tzset()
print('Australia/Melbourne in string form:',time.asctime())
os.environ['TZ'] = 'Asia/Kolkata'
time.tzset()
print('Asia/Kolkata in string form:',time.asctime())