The expression “8!” is a mathematical formula (it means “8 factorial” which means you multiply 8 times every integer below it. So 8! = 8*7*6*5*4*3*2*1). It’s just a happy coincidence that February (when it has 28 days) has exactly this many minutes. 60 minutes (5*6*2)* 24 hours (8*3) * 28 days (7*4) = 8*7*6*5*4*3*2 | Emily Calandrelli

Math on Khan Academy