HALO 4 DOUBLE XP HELP MEEEE

Hey, I just got a lot of double xp from a friend and I was wondering if I applied it to my gamertag. After the 31st which is the last day you could bank your codes on dewxp.com Will the double xp still be available after very single match even after the 31st. In other words will double xp work after the 31st?

“Codes can be entered on the Website until 11:59:59 pm ET on 1/31/13; any unapplied XP Matches remaining on or before 3/31/13 will be forfeited.”

Source: Official Rules