Some regions use offsets of 30 or 45 minutes instead of whole hours from the reference time.

The longer version

Not every place sits neatly an hour from the reference. Some countries lie between two zones and chose the midpoint, giving offsets such as five and a half hours. A few went further and picked quarter-hour steps, producing differences of 45 minutes. The result is a clock that matches local daylight better than a rounded hour would.

The motive is usually practical: a large country may want one clock for the whole population, and the average longitude lands off a whole hour. Travellers find such offsets awkward, because meeting times, transport timetables and software all assume whole hours far more often than they should. Some systems simply discard the fraction and show a wrong time.

Where this entry sits

These facts wander through clocks, calendars, time zones, and the long human effort to measure passing hours. You will find leap years, odd month lengths, ancient sundials, and the reasons modern timekeeping works the way it does. The full list sits on the Time and Calendars page, where every entry is listed in order.