So the Institute of Medicine proposed that residents be required to get five continuous hours of rest for every sixteen hours on duty.

VOA: special.2010.07.13

Two hours after Apollo Thirteen went around the moon, the astronauts fired the rocket for five minutes.

VOA: special.2009.07.22

Five hours after the explosion, flight controllers advised firing the rocket for thirty-five seconds.

VOA: special.2009.07.22