So my new phone was displaying time a XX:XXam then later YY:YYpm. I wanted 24hr clock but couldn't find it. Eventually when checking the format I realised it was already set to 24hr clock instead of 12hr. So I changed it to 12hr (no change) then put it back to 24hr and now it is expressing the time as ZZ:ZZ. No AM or PM. Obviously it was confused and befuddled but now I have had to say "No,
like this"