How do you prepare a defense against a time stop? At high levels its possible, but at low levels there is next to nothing you can do against it, except hit them with something. And if they evade it, that's basically GG. 

so in theory, sure, if you know a time stop is coming(in a non-metagamey way), you can stop it, by physically hitting them. there is really not much else you can do really, not at low to mid levels. 

time is one of those things that can get really out of hand.

a work around, however, is it not affecting PCs(or anything that are touching) during the duration of said time stop.