It’s a leap year, and Chipotle announced it is celebrating February’s extra day by offering its Rewards members free guacamole on digital orders placed exclusively on the Chipotle app and website on Thursday, February 29.

“Our guests understand that ‘guac is extra’ is not just a phrase, it’s a testament to the quality and freshness of our real food,” said Stephanie Perdue, vice president of brand marketing. “There’s no better way to celebrate an additional day on the calendar than with our iconic guacamole not being extra.”

The brand is kicking off the campaign early on February 26 with a gamified scavenger hunt on Instagram, rewarding 29 fans with free guacamole for a year. 

Chipotle said it is building on its history of hiding keywords for free food in plain sight with its new Extra Day, Extra Codes promotion, a gamified scavenger hunt. Chipotle is challenging fans to uncover keywords hidden in its Instagram content leading up to the “extra day” for a chance to win free guacamole for a year. Twenty-nine winners will be chosen in total to receive the free dip for a year.

From Monday, February 26 through Wednesday, February 28, participants will be challenged to uncover 29 keywords hidden in the content and captions on Chipotle’s Instagram page.

Beginning at 9 a.m. PT each day, ten keywords will be available on February 26 and February 27, and nine keywords will be available on February 28. 

In January, Chipotle announced that it plans to hire 19,000 workers for “burrito season.” Last year, it developed a “time to finally try Chipotle” promotion around Cinco de Mayo.