Lucky 13

Mere’s formula for the calculation of when to celebrate:

Approximation:  NO MORE KIDS = SUMMER BREAK = FREEDOM = CELEBRATE = (last day of school) - (current date) = 13

Actual:  NO MORE KIDS = SUMMER BREAK = FREEDOM = CELEBRATE = (last day of school) - (current date) - 2*(1/2(1 day of school)) = 12

 EDIT: my math teachers would be disappointed…I forgot my units on my answer… 13 days and 12 days