S1·E30 Hercules and the All Nighter

In order to stay up all night studying for exams, the boys go to the cave of Morpheus and beseech the god of sleep to hold off for a few days. Morpheus resists the idea, but when Hercules accidently puts him to sleep, Icarus won't let him wake up, causing all of Greece (and parts of Persia) to stay awake for a week while chaos breaks loose and insomnia related disasters pile up.