Unnamed Days
From WikiRaider
Unnamed Days are an essential element in the ancient Maya Calendar. They were the five days at the end of each Haab cycle, bringing it up to the 365 days of the solar year. Theses days were generally considered unlucky.
Tomb Raider Underworld
In the Southern Mexico Section of Tomb Raider Underworld there is a level called The Unnamed Days, deriving its name from these days.