What is the orgin of the phrase graveyard shift?

Answer 1

In the 1800's, medical science wasn't what it is today, and people who were merely in a deep coma were often pronounced dead. When their coffins were dug up ( who knows why....flooding perhaps, or by vandals) they would occasionally find scratch/claw marks on the inside of the coffin lid, indicating that the person had regained consciousness and tried to fight their way out. The practice then became to attach a bell on a long cord to the hand of the supposedly deceased. During the day, the cemetery attendants would listen for bells ringing, but the shift of workers whose sole job was to listen for the bells of the buried but undead, from midnight to dawn, became known as the Graveyard Shift.

I forget the time period but when medical science was starting to make bigger advancements in creating formal education process, knowlege started to advance more rapidly. The growing number of medical students were having a harder time getting bodies to practice on so they began going on cadaver hunts for recently buried bodies. After a while guards were needed at night time to prevent grave robbing. That's why graveyard shift is only at night

Answer 2

The idiom "Graveyard shift" started a long time ago when it was harder to tell if somebody is dead. They would put a rope in the coffin leading up to the surface where there would be a bell. A man, late at night, would come and listen for any ringing bells. They called this the graveyard shift.