Figured it out: It’s not changing the time it’s reporting, but the format in which it’s reporting it. In other words, in the US we generally don’t use 24hr time, so at 14:14 we would say 2:14PM, but Brave doesn’t include the PM and puts a leading zero in the hour, so it shows 14:14 as 02:14 when it’s set to US, but 14:14 when set to UK or Australia. To a most US people (other than those in the military or otherwise accustomed to 24hr time), it wouldn’t be a big deal, but to someone used to 24hr time all the time, it would look like a 12hr difference.