24 Hour Clock on MacBook Air

I had this as well, and the Date & Time setting wouldn't change it back. Eventually I found another setting in Control Center, scroll to the bottom under "Menu Bar Only", there's a Clock Options... button, then a popup with a toggle for "Use a 24-hour clock". This one finally turned off the 24-hour clock. I assume having two settings for the same thing is a bug.

Incidentally, both of these settings can be found in "System settings..." by searching for 'clock'.

christopher_o218 wrote:

I followed the steps, but when I hover the cursor over it, it doesn't light up, and when I click it, nothing happens. It is stuck on the 24-hour clock option. How do I change it back?

settings - date & time