According to a report on Eurogamer, Steam's annual Winter Sale will officially begin on December 22 and run through January 2.
There are no specific details on what type of sales there will be, as it hasn't been officially announced by Steam themselves, but Last year the 2015 Steam Winter Sale the sale offered heavy discounts on "thousands of games and software." Be sure to mark December 22 on the calendar to end up buying way more games than you plan to buy.
For those looking for a good deal on games, always be sure to check GameZone first. We cover not only Steam sales but console game sales as well. Make sure you're getting the best deal on games this year.
