Does anyone know if different pharmacies have different policies about how long before your medication runs out that you can have it refilled?

I recently switched pharmacies. At my old pharmacy, they wouldn't refill my Klonopin (a controlled substance) any sooner than 2 days before I would run out. I always took it as directed, so I never took more than 30 pills in 30 days. Now at my new pharmacy, the pharmacist said I could get it filled 6 days before I run out. This would be good, because I will run out of my Klonopin 5 days into my upcoming vacation abroad. That would mean I'd have to go to this new pharmacy the day before we fly out, and on a Sunday.

I'm worried that I'll get to the pharmacy and they'll say "No, it can't be filled until (such and such date into my vacation)." I'll call again and ask the Friday before when it can be filled. If that date changes, I'm going to have to call my psychiatrist and ask him to prescribe an emergency supply. Luckily my psychiatrist is very good at returning calls and calling in meds. He said I could even call his cell phone on Sunday, but I'm worried it will be a scary rat race.

When I saw the pharmacist the last time I asked if I could just take Ativan instead of Klonopin for some days. He said no, that they work differently.