No...what's Labor Day...? But, White Day comes after Valentines...on Valentines, girls give chocolates to boys...although it's okay to give them to friends who are girls, too. The chocolates are either honmei-choco or giri-choco...the second one is obligation, the first is more...romantic...?

[ SHE'S NOT SURE ABOUT ROMANCE IN GENERAL... ]

Anyway, on White Day boys give return gifts for the chocolates they received...I think you give cookies or that sort of thing...or white things...