Zoap, it senses whenever you even change the DS System you're using, even if you don't touch the clock. I use my DS original and a DSi XL and a 3DS, and every time i switch machines i have to wait an extra day to Game Sync. I think if you have your DS's synchronised to each other exactly, you *might* avoid it, but i highly doubt that as my XL and 3DS are set to correct time (only my DS Original isn't, because of RNG'ing).
As long as you keep it in one DS system, and don't touch the clock, you'll be fine.
EDIT: I do know for sure that changing the clock back won't work, as it's not the time that matters, but the fact the time changed suddenly that will affect Game Sync. I tried it once to get around the 24hr extra limit and it didn't work.
As long as you keep it in one DS system, and don't touch the clock, you'll be fine.
EDIT: I do know for sure that changing the clock back won't work, as it's not the time that matters, but the fact the time changed suddenly that will affect Game Sync. I tried it once to get around the 24hr extra limit and it didn't work.