The term “Cereal Friday” is a custom in which friends/peers gather in a lunchroom or cafeteria to consume cereal on any given Friday. While Cereal Fridays usually occur weekly, they can also be random and skip weeks.
Person 1: Shit man it’s Cereal Friday!
Person 2: Hell yeah, my bus leaves in 5 minutes so I’m gonna fucking DOWN this cereal.
Alternate Example-
Person 1: Yo it’s Cereal Friday and I don’t have enough money for milk, could you get me one?
Person 2: Sorry I can’t, but you can have the milk that’s left after this bowl when I’m finished.