It’s not that simple as people has this urge to associate 12pm to noon and 12am to midnight. Just look at china where the whole country is under a single timezone despite spanning from UTC+05:00 to UTC+09:00. People on xinjiang ended up using their own unofficial timezone (UTC+06:00) for their daily activities instead of using china’s official timezone (UTC+08:00) because it’s inconvenient to them.