convert datetime with timezone to proper format in python

Question

I have a variable

date_1 = "2023-04-14T09:57:40-04:00"

how to convert to proper format - 2023-04-14T05:57:40Z

Expected ouput - "2023-04-14T05:57:40Z"

Answer 1

Essentially, you're looking to convert a date/time string with a UTC offset to UTC. You can do that like

from datetime import datetime, timezone

date_1 = "2023-04-14T09:57:40-04:00"
utc = datetime.fromisoformat(date_1).astimezone(timezone.utc)

print(utc)
# 2023-04-14 13:57:40+00:00

print(utc.isoformat().replace("+00:00", "Z"))
# 2023-04-14T13:57:40Z

Notes:

• a UTC offset like -04:00 is not a time zone to be precise; multiple time zones can share the same UTC offset at a given time
• as Matt Johnson-Pint commented, UTC offsets are subtracted from the give time to get UTC, so 9 am with -4 hours offset becomes 1 pm UTC
• Python currently does not offer you to represent UTC as 'Z' when formatting to string, thus the replace
• datetime module docs

Answer 2

Please refer to the other answer posted, this one does not properly convert UTC.

import datetime
import calendar
date_1 = '2023-04-14T09:57:40-04:00'
datex, timez=date_1[0:-6], date_1[-6:]
timed = datetime.datetime.strptime(datex, "%Y-%m-%dT%H:%M:%S")
timez = datetime.datetime.strptime(timez.replace(':',''), "%z")
output=datetime.datetime.fromtimestamp(calendar.timegm(timed.timetuple()), tz=timez.tzinfo).strftime("%Y-%m-%dT%H:%M:%SZ")

Code first splits datetime (datex) and timezone (timez). Converts datex to datetime.datetime then epoch, and convert timez to datetime. Finally converting datex to UTC time based off current timezone, then formats the datetime.datetime object to string.

Previous answer (not working)

import datetime
import calendar
date_1 = "2023-04-14T09:57:40-04:00"
timed = datetime.datetime.strptime(date_1, "%Y-%m-%dT%H:%M:%S%z")
output=datetime.datetime.fromtimestamp(calendar.timegm(timed.timetuple()), tz=timed.tzinfo).strftime("%Y-%m-%dT%H:%M:%SZ")

It's a bit long, but it should work! The program first converts the date_1 to a datetime.datetime object, then it converts it to epoch time, from which it converts this epoch time to the UTC timezone, and finally formats the epoch time to the output string.

Please let me know if this works for you.