12 Hour vs 24 Hour Clock Formats
Both clock formats represent the same local time. The best choice is mainly about familiarity and context.
12 hour format
The 12 hour format cycles from 1 through 12 and uses AM or PM to distinguish morning and afternoon periods.
24 hour format
The 24 hour format runs from 00 through 23 and does not need an AM or PM marker.
Pick for the audience
Use the format that is easiest for the people viewing the screen. A fullscreen clock should communicate instantly rather than require interpretation.
Ready to try it?
Open the matching browser tool and switch into fullscreen when you want the display to take over.