They did a similar promotion last year with the introduction of the Fresh Baked Buns. They call it "MondayBunday."
The new burger was introduced as part of tie-in for the upcoming X-Men: Days of Future Past movie and features twice the amount of bacon over a regular Western Bacon Cheeseburger.
You can find the coupon on the Carl's Jr. website here and on the Hardee's website here. There's a specific coupon for each of the next five Mondays (specifically for 3/31/14, 4/07/14, 4/14/14, 4/21/14, and 4/28/14).
