"The Jail Double XP Event Ends in 8h, 52m, 45s. Your double XP is not active. Toss a share-jail at the bottom of your screen to add time to it. You can stack time by doing multiple shares. "

Just as a heads up, the jail page XP tier % listed next to how many busts you have is showing what you *would* be earning if you had double XP active.  Please refer to the giant red box above it which tells you if double XP is active or not to determine if double XP is active or not :P