In Lebanon, when someone says it’s 3 o’clock and it’s daytime, we all know they mean 3pm and not 3 o’clock in the morning. So you can imagine my confusion when I moved to France for a year where everyone uses the 24-hour format and I had to do the mental gymnastics everytime (pun intended) to figure out the correct time. There are countries where this is the norm and others where it’s not, but until now, you had to manually pick that setting in your Android phone. Not with P though.
A new setting showed up in Android P (we can traced it back to DP3, but it might have been added earlier) under Date & time for Automatic 24-hour format. Enabling it greys out the manual toggle below it and relies on your locale to set the default format. If you disable it, you can still turn on 24-hour mode or not.
Left: Date & time settings in Android 8.1. Right: In Android P DP4.
If you live in a country where 24-hour format timing is the norm, which according to Wikipedia includes many non-English speaking countries, you’re probably happy about this setting. Our tipster told us it was enabled by default for him when he updated to DP4, but it was disabled for me. Odds are, it will be activated by default on new devices.