Testing on eggs, pendants and stuff. And not involving Horntail.

In case it's too confusing: I think your computer's clock is the time the 7th day market merchants use instead of the maple time that is seen on boat clocks.

The client side quests use your computer's clock. The server's part of the quests use server time (and the NPCs appear/disappear based on that)

So it'll just give you errors if you try to do anything outside Nexon time.