Python Timezone conversion

Question

I am looking for a quick way to type in a time and then python convert it into other timezones ( maybe up to 10 different timezones )

Sorry. I am not familar with time in python at all, if someone could put me in the right direction I would really appreciate it.

Answer 1

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)

Answer 2

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?

Answer 3

For Python timezone conversions, I use the handy table from the PyCon 2012 presentation by Taavi Burns.

Answer 4

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")

Answer 5

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')))

Answer 6

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']