Indicator Applet Complete Clock Format

[lah7]

There's also the command line version - but "24-hour" not "12-hour":

Set the date/time indicator to 12 hour time

There's two implementations of the date/time on a MATE panel: MATE Clock Applet (default on most distros) Date/Time Indicator ( and default) The Indicators program can customise a few things, but it lacks the option for setting the format. For now, this can be set from the Terminal. Ayatana Indicators (>= 21.04) gsettings set org.ayatana.indicator.datetime time-format '12-hour' 20.04 gsettings set com.canonical.indicator.datetime time-format '12-hour'