Not everyone wants to change the 3DS clock. There are people, me included, who have digital versions of games which are time sensitive, and messing with the 3DS clock puts you in a "penalty" of sorts since the 3DS clock also messes with the time in the digital games, even if you put it back.
I use the in game clock because I would rather not be penalized in my other games.
This is why I stay away from digital games.
I don't know what to say to this. Go ahead and TT to that time or whatever. IMO, waiting, if you're not gonna use the 3DS clock, is the easiest thing to do.