Question about the birth control pill please...? see details?

Normally I take my birth control pill at 7 every morning before school. However I've started to not have to get up early on teh weekends anymore and I don't wake up til about 11 and i take my birth control pill then.

is this not effective?
Does this mean I have to wake up at 7 am on weekends?
Can I change my time to 11pm with the next cycle of birth control if it's absolutely necessary?

Keep in mind I don't use my birth control for birth control, but for regulating my period and helping out with my previous skin problems.

I ve been on the pill for 10 years. The doctor tells you to take the pill at the same time everyday so that you can get in a routine and remember to take your pill. Its okay to change the times, b/c the whole focus is to take the pill everyday. The time really doesnt matter. Trust me. Its been working for me.

If you take them at 11 p.m., you'll be fine. Just be consistent.
I don't think that a few hours will make much of a difference. I rarely took my pills at the same time every day and my period was regular and my husband and I used no other type of birth control (condoms or anything else) and I didn't get pregnant until after I stopped taking the birth control pills.
Personal Experience
No Way...as long as you take it every day it will be effective (especially if you are only regulating with them) All though taking them at the same time every day makes them more effective, it is definitely not going to render them useless by taking them 4 hours later!
Since you only use it for periods and skin this is fine however if you plan on being sexually active in the near future I would pick a better time to take it as once you need it for birth control you need to take it at the same time every day.
If you were using bcp's for birth control, I'd say it's very important to keep the level of hormones in your blood stream constant, by taking the pill at exactly the same time each day, + or - 30 minutes. But since it's for regulating your periods and skin problems, I don't think it's a huge issue to be a couple hours off. Just my opinion.