Usage: when ZONE [ZONE ...], where ZONE is a zone name, or part of it.
Example:
$ when brisbane utc
Saturday 2021-05-08 (EEST +03:00)
Zone Δt Time
Local Sa 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Brisbane +7:00 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Su 1 2 3 4 5 6
UTC -3:00 21 22 23 Sa 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Download the binary from https://github.com/jupj/when/releases/
Or install from source (requires a recent version of Go installed):
$ go install github.com/jupj/when@latest