How long does it take to get my birth certificate if I go in person?

I live in California. I was just wondering if it takes less time to get my birth certificate if i went in person than if i got it through the mail or online? Is it possible to get it that same day?How long does it take to get my birth certificate if I go in person?
In most places, you should be able to pick it up the same day if you go in person. But to be safe, you should call the offices first to be sure.