Can occur on a Sunday evening bust most often Monday through Thursday. Caused by the excess consumption of alcholic beverages the previous evening, resulting in a craptastic hangover the following morning, most certainly resulting in a "sick" call into the office.

Invented in Borat's movie. It is said, when something great happens.

When you wake up the next morning after a heavy night of drinking, unable to go to work you phone and call in “sick”