Previously:

• Python – Create current datetime object with timezone
• Python – Specify datetime timezone using pytz

If we have a datetime with timezone, we can also convert it to UTC datetime using pytz.

import pytz
import datetime

local_tz = pytz.timezone ("Asia/Hong_Kong")
datetime_without_tz = datetime.datetime.strptime("2015-02-14 12:34:56", "%Y-%m-%d %H:%M:%S")
datetime_with_tz = local_tz.localize(datetime_without_tz, is_dst=None) # No daylight saving time
datetime_in_utc = datetime_with_tz.astimezone(pytz.utc)

str1 = datetime_without_tz.strftime('%Y-%m-%d %H:%M:%S %Z')
str2 = datetime_with_tz.strftime('%Y-%m-%d %H:%M:%S %Z')
str3 = datetime_in_utc.strftime('%Y-%m-%d %H:%M:%S %Z')

print 'Without Timzone : %s' % (str1)
print 'With Timezone   : %s' % (str2)
print 'UTC Datetime    : %s' % (str3)

Done =)

Reference: StackOverflow – How do I convert local time to UTC in Python?