Babies are born at all hours around the clock. They show up when they're ready! I heard this folk wisdom all the time when I was pregnant with my daughter in 1993. As it turned out, Sarah was born (with just a little nudge from Pitocin, the synthetic version of the hormone oxytocin) at 6:41 on a Saturday evening.
Just two generations ago, most babies did come around the clock.
Now, though, most babies born in the U.S. arrive Monday through Friday between 8 a.m. and 6 p.m.