7 on the 7th

""The 7 on the 7th playlist exists specifically to give players a shot at that elusive achievement."."

- Shishkas in-game description for Halo 3's 7 on the 7th playlist

Description
7 on the 7th is a playlist only on the 7th of each month. The 7 on the 7th playlist exists to ensure that people have an opportunity to get the Seven on the Seventh achievement.

Maps Played In 7 on the 7th

 * Avalanche