Mine broke at 6:15pm i had my son at 10:10am the next morning. Mine broke before contractions because of my sons position.
Most people's water doesn't break to start labor. Usually they start contracting and the doc eventually breaks it. Mine did but they put me on pitocin anyways without even telling me... They didn't even give me a chance to start dialating on my own. I was in labor for 20 hours.
It varies. With my first it was 16hrs, with my second it was 3, with my third it was 5. But doctors do everything they can to ensure baby comes within 24 hours of your water breaking to prevent infection.