It is, there are a couple of timezones where not only there is a hour difference, but even a 30 and 45 minutes difference. India is UTC +5:30, and Lord Howe Island is UTC +10:30 / +11:00 and New Zealand, Chatham Islands is UTC +12:45 / +13:45, Iran is UTC +3:30 / +4:30 and so on. Where the format is X / Y, that means X is Standard Time, and Y is Daylight time.

Messy.

I think the full list can be found here: https://www.timeanddate.com/time/time-zones-interesting.html

You can use a Bash script that can give you an exhaustive list based on files from /usr/share/zoneinfo/, i.e. find timezones with non-whole hour offsets.