Date format in user control panel

[Philotas]

I seem unable to change the way date and time is displayed here at the forum; any changes I do won't save.

It reads "Your changes have been saved.", but that's a lie.

I find a.m. and p.m. confusing, so that's why I am asking (it seems some of the options are 24h?).

 

[MeteorWayne]

You may have to log out and log in again for the changes to take effect.

 

[Philotas]

That doesn't seem to work. When you change format and save, the choice you've made is already reset.