Exercise 2 solution

    from datetime import datetime
    from zoneinfo import ZoneInfo

    names = ["Europe/London", "America/New_York", "Australia/Sydney", "Asia/Kolkata", "Asia/Tokyo"]
    for name in names:
        zone = ZoneInfo(name)
        jan = datetime(2026, 1, 15, 12, tzinfo=zone).utcoffset().total_seconds() / 3600
        jul = datetime(2026, 7, 15, 12, tzinfo=zone).utcoffset().total_seconds() / 3600
        print(f"{name:<20} Jan {jan:+.1f}  Jul {jul:+.1f}  {'changes' if jan != jul else 'constant'}")

Output (run, and exactly as shown):

    Europe/London        Jan +0.0  Jul +1.0  changes
    America/New_York     Jan -5.0  Jul -4.0  changes
    Australia/Sydney     Jan +11.0  Jul +10.0  changes
    Asia/Kolkata         Jan +5.5  Jul +5.5  constant
    Asia/Tokyo           Jan +9.0  Jul +9.0  constant

Explanation: a named zone is a set of rules, so its offset depends on the
date. Three of these zones change offset between January and July; the
other two do not. Notice that the southern-hemisphere zone is on its larger
offset in January, the opposite season from the northern ones. A fixed
timezone(timedelta(...)) could not reproduce any of the changing zones.