Days of FIFA is a yearly event created by Electronic Arts to celebrate the holiday season. It takes place during the period preceding Christmas day, in a number of days corresponding to the FIFA edition. To FIFA 17, for example, '17 Days of FIFA' starts 17 days before Xmas and ends on December 25.
The Days of FIFA is announced as the biggest social giveaway and that's what exactly it is: during the promotion, EA Sports offers special daily gifts to their social channels followers. Unlike what most people think, it has nothing to do with FUTMas, a completely different promotion that also takes place in December.
Who follows the Facebook, Twitter or Instagram EASPORTSFIFA social channels and replies to their posts, get eligible to win FIFA copies, signed jerseys of popular players or clubs, signed boots, FUT in-game items, free Ultimate Team packs and more FIFA and football related merchandising.