ComiXology has unveiled its own version of an Advent calendar with a countdown called the "12 Days of Free Comics."

The promotion is exactly what it sounds like: Each day between today and Dec. 20 (alas, not Christmas), the company is offering a different digital comic for free. To kick things off, there's Batman #13, by Scott Snyder, Greg Capullo, James Tynion IV and Jock, the first issue in the "Death of the Family" storyline. Day 2 is ... well, you'll have to check back with comiXology to find out.

“Over the course of these 12 days we’re making holiday giving easier than it’s ever been,” comiXology co-founder John D. Roberts said in a statement. “These twelve days aren’t just to give back to the fans that have made comiXology so great but also to let those fans share the love of comics with everyone they know.”

Fair warning, though: Readers have just 24 hours to claim their free comic; by the time Day 2 of the promotion arrives, Batman #13 will no longer be available (for free, at any rate; it'll regularly cost you $2.99).

You can sign up for daily alerts, or follow the comiXology blog to find out when the new freebies are available.