xclock — Display the time in analog or digital form. More information: <https://manned.org/xclock>.

Display an analog clock

xclock

Display a 24-hour digital clock with the hour and minute fields only

xclock -digital -brief

Display a digital clock using an strftime format string (see strftime(3))

xclock -digital -strftime {{format}}

Display a 24-hour digital clock with the hour, minute, and second fields that updates every second

xclock -digital -strftime '%H:%M:%S' -update 1

Display a 12-hour digital clock with the hour and minute fields only

xclock -digital -twelve -brief