The one day where all your pending bank transactions go through before you can deposit or transfer money to cover them.
Duder 1: "Fucking school loan payment, grocery store, vet bill payment and my dinner out Saturday night all went through today! I got like three overdraft fees son! I'm broke!"
Duder 2: "You fucked up."
Duder 1: "Damn I want to choke somebody. Fuck this day of overdrafts."