In celebration of 115 Day, Call of Duty Black Ops 4: Zombies players can get double XP and other bonuses for a limited time.
A blog post on the Treyarch website explains January 15 marks 115 Day and is a nod to the element 115, which plays a part in the deeper Call of Duty Zombies lore. For players, this means until January 18 you can earn double XP, double weapon XP, and double Nebulium Plasma across all platforms.
The Nebulium Plasma may be especially helpful for PS4 players, as three new epic craftable elixirs are being added this week. Perk Up will grant 4 new random perks, Refresh Mint resets cooldowns for your team, and Conflagration Liquidation gives you a bonfire sale power-up. There have also been some balancing changes to existing elixirs.