I recall I asked some time ago why Time&Date is under System and not Settings. The answer was that this is self changing parameter while all others settings in rb are not. Still I think Time&Date belongs to Settings and anyone is familiar with the fact that time passes away and you can do nothing about it :-)
The fact that time&date is under settings in every single consumer device (excluding rockboxed DAPs) I had a chance to fiddle with is valid point IMO. My 0.03 PLN Marcin