I never use time travel in Virtual Families, as I don't want to age my little peeps any faster than necessary. The money will come quick enough without resorting to doing it.

However I do have to admit I used time travel in the villager games, as the building projects can be quite mundane, and it takes forever otherwise to get enough tech points to advance. Though I did it as TyphoidMary suggested...only a little at a time...never more than half hour or so. Then you can pause your game and reset the clock without it affecting appointments and such.