xkcd #3140: Biology Department
Title text:
Welcome to the Linguistics Department - It has been [2] [DAYS] since someone noticed that the Biology Department sign has a one-day-long singular/plural disagreement after it resets.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3140/
Some say this was the inspiration for the game but I never bothered confirming.