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zoneinfo Module

The zoneinfo module provides IANA time zone support for accurate timezone handling, including daylight saving time.

Complexity Reference

Operation Time Space Notes
ZoneInfo() O(1) O(n) Load timezone data; cached after first load
Localize datetime O(1) O(1) Apply timezone

Working with Time Zones

Using Timezones

from zoneinfo import ZoneInfo
from datetime import datetime

# Create timezone - O(1)
est = ZoneInfo("America/New_York")
pst = ZoneInfo("America/Los_Angeles")

# Create datetime with timezone - O(1)
dt = datetime(2024, 1, 15, 12, 0, tzinfo=est)
print(dt)  # 2024-01-15 12:00:00-05:00

# Convert timezone - O(1)
dt_pst = dt.astimezone(pst)
print(dt_pst)  # 2024-01-15 09:00:00-08:00

# Get timezone name - O(1)
print(dt.tzname())  # EST