Currently Call of Duty: Ghosts is running both a double XP in Multiplayer and Squads modes and 50% off sale from 21 February 10 AM/PST until 24 February 10 AM/PST, furthermore, Call of Duty: Ghosts is free to play (for multiplayer) until February 23rd 1 PM/PST. For those that currently own Call of Duty: Ghosts, now is the best time to get your multilayer levels up with the double XP. And for those that have yet to buy the game on PC, can now try it for free and get it at 50% off if they buy it. To download purchase Call of Duty: Ghosts, please see its Steam page.
For those outside the PST timezone, please see the following clock if you unsure that the current PST time is here.
Added note: This does double the XP cap.