It doesn't "go bad" per se but if not kept in appropriate conditions it will degrade. Either the LSD molecules are intact or they aren't.
Ideally, you want to put your tabs in an airtight, opaque container of some sort, then put that in the freezer. Light, heat and moisture all speed up the degradation of LSD. Room temperature is too high to store it for more than a few days without notable degradation. If you keep it airtight, dark and in the freezer, it should be fine for a few months, probably years.
Also, make sure not to take your tabs with tap water. Tap water is typically chlorinated, and even the small amount of chlorine they put in it can destroy the LSD as well. If you have a drink immediately before or while taking the tab(s), make sure it's from a bottle or can and not a tap.
edit: I find it funny that you find it funny to call acid scarce. Nothing seems scarce when you have a supply, I suppose, but I thought it was pretty common knowledge that LSD in the US is quite scarce these days. The combination of major busts under the Bush era DEA and the rise of RCs has reduced availability and flooded what market there is left with RCs passed off as lucy. I put little stock in reports that "acid is coming to town soon" because 95% of those reports I hear turn out to be false.
