How long should/can you go without a perm?

Hello,
I was wondering how long should/can you go w/o a perm before causing some damage. I'm leaving the country at the end of this month and I'll be gone for 2 months. I'm going to get a perm like the day before I leave. But until that time, it's been like a little over 2 months since I've gotten my last perm. I want it to be fresh when I leave the country. I usually never wait this long to get a perm, but I'm wanting to know is it ok to to this long w/o. Thanks

Brigitt wrote: Better 2 months instead of 3. Because perm can cause your hair dry by underprocessed.

I mean this 3 months can cause dry.