24-hour clock format wont turn off

Half way through the day today i looked to check the time and my watch is now showing the clock in 24 hour format, in the facer settings it is set to 12-hour as well as on my watch and my phone, this happened out of the blue. I was not doing anything on my watch nor my phone when it changed. Why? And how do i make it go back to the 12-hour format?

Hi, is it happening with a specific design? maybe the watchface has both options 12/24 or maybe the watchfaces only has 24h mode. Just an Idea. Please give us more info.