Twitter is abuzz with posts mentioning 115 Day. What is 115 Day, and why is everyone talking about it?
What is 115 Day?
115 Day, or 15 January (1/15, unless you’re in the UK, in which case it’s 15/1), is a day of celebration for Call of Duty fans.
For fans and developers alike, 115 Day is an annual celebration of zombies.
This year, Zombies Free Week began on 14 January and will run through until 21 January. There’s more in store, but developers Treyarch haven’t revealed the full details yet.
Typically, Treyarch divulge upcoming additions to Call of Duty’s Zombie mode on this day, but fans will have to wait a little longer.
They did, however, release a teaser to their fans on Twitter, on 8 January.
Why does 115 Day fall on 15 January? The specific number 115 is a reference to Element 115 from Call of Duty.
What is Element 115, and what does it have to do with zombies?
For the uninitiated, Element 115 (Moscovium or Divinium in-game) appears in the Black Ops series, as well as Call of Duty Online.
Within the narrative of the game, the Germans discovered Element 115 during World War I in northern France, in Dimension 63, following information contained in Pablo’s Diary.

Later, Group 935 conducted clandestine experiments on the substance in secret facilities.
However, it was discovered, one of the side effects of applying Element 115 was the reanimation of dead cells. As a result, the Germans conducting the experiments used zombies effectively as super-soldiers.
But they soon realised that the zombies were uncontrollable, and would lead to the destruction of mankind.
Fans of the franchise will have to wait a few more hours to see what this year’s big reveal is…
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