tz helps you schedule things across time zones. It's an interactive TUI program that displays time across the time zones of your choosing.
Run tz with no arguments to show the local time, as well as the UTC time zone. It gets more useful when you pass some time zones to the program, to list those below the local time zone.
For now, you need to select the time zones from the tz_data list. Yes, there are plans to make this friendlier for humans too. You're welcome to file an issue about it. I enjoy reading those.
If you would rather not type the list everytime, you could set an alias for your shell, or use the TZ_LIST environment variable with a semi-colon separated list of tz data zone names (see Configuration below). Command-line arguments trump the environment variable.
I provide linux/amd64 builds for "official" releases, and you can build from source for your favorite architecture. Kind souls have also packaged the program for other OSes.