python-handle-timezones.md

Handling timezones in python

• Talk - Benjamin "Zags" Zagorsky: Handling Timezones in Python

TLDW

Use ZoneInfo

from zoneinfo import ZoneInfo

Current time

from datetime import datetime, timezone

datetime.now(timezone.utc)

Current date

from datetime import datetime
from zoneinfo import ZoneInfo

datetime.now(ZoneInfo("Europe/Stockholm")).date()

Convert datetime to date in a timezone

dt = datetime(2022, 7, 8, tzinfo=timezone.utc)

dt.astimezone(ZoneInfo("Europe/Stockholm")).date()

>>> date(2022, 4, 5)

Display UTC time as local time

dt = datetime(2022, 7, 8, tzinfo=timezone.utc)
tz = ZoneInfo("Europe/Stockholm")
dt.astimezone(tz).strftime("%x %X")
>>> '04/05/22 22:00:00'

Convert ISO-8601 string to UTC datetime

dt_str = "2022-07-08T02:00:00+02:00"
datetime.fromisoformat(dt_str).astimezone(timezone.utc)
>>> datetime.datetime(2022, 7, 8, 0, 0, tzinfo=datetime.timezone.utc)

Duration math in UTC

tz = ZoneInfo("Europe/Stockholm")
local_dt = datetime(2022, 7, 8, 0, 38, tzinfo=tz)
local_dt.isoformat()
>>> '2022-07-08T00:38:00+02:00'

new_dt = local_dt.astimezone(timezone.utc) + timedelta(hours=2)
new_dt.astimezone(tz).isoformat()
>>> '2022-07-08T02:38:00+02:00'

Calendar math on dates

tz = ZoneInfo("Europe/Stockholm")
local_dt = datetime(2022, 7, 8, 0, 38, tzinfo=tz)
local_dt.date() + timedelta(days=120)
>>> datetime.date(2022, 11, 5)