I'm running SlimKat (4.4) on my Note II and since my update from 4.2 JellyBean I switched my system language to English UK because Americans can't speak English. With that came some unexpected surprises, such as the conversion to metric units, such as date format, time being 24-hour instead of 12 hour, temps, and regional lockouts, with the latter being a serious problem, particularly with Amazon services, such as Music, though other apps aren't too fond of this change. However, I rather like the metric system so far as it just makes more sense.
So, how do I retain system-wide metric units while letting my apps know that I'm actually in the US (because GPS and cell towers aren't confirmation enough), for lack of better phrasing? I'm getting kinda tired of my Starbucks app letting me know my balance in GBP instead of USD, or Amazon telling me I need to re-new my Prime membership even though I'm already a Prime member (because I'm not a amazon.co.uk member). I'm also sick of tripe-checking my alarms for AM or PM and I have missed work because of a mis-set alarm.
The issue is with apps, not with the system.
You can specify date and time formats in system settings. There's "Use 24-hour format" checkbox in particular.
Which units use for length, weight and temperature is entirely dependent on implementation of each app. Some have settings for that, some don't.
I figured, but I still think it's stupid that I'm subject to regional lockouts because my preferred language isn't the official/primary language of my country of residence. I toyed around in the settings and got things set properly: 24 hour clock, dd/mm/yy settings, and in the Calendar app, the week starts on Monday instead of Sunday - again makes much more sense to put the weekend at the end of the week - why the calendar weeks starts on Sunday in the US is beyond me.
Unfortunately, that doesn't solve ALL my problems - even some websites, such as Wunderground, automatically determine the units with no settings that I can find, so it seems I'm stuck with temperatures in Fahrenheit.
Thanks for the help - I had assumed the clock and date format would be in the app, and when I couldn't find it, I came rushing here. Should have known to look in system settings...