TimeConv

Converts between UTC(+|-)\d+ time zones. Uses 24 hour time.

Use:

$ # Convert UTC+3 13:00 to UTC-10
$ timeconv +3 -10 13:00
02:00

$ # If you get the args wrong (or there aren't any) it will ask you
$ timeconv
From: +3
To: -10
Time: 13:00
02:00

$ # But only the wrong args
$ timeconv +3 --10 13:00
To: --10
To: -10
02:00