special holidays generally. So maybe once in the spring, Summer, and certainly Thanksgiving and Christmas, New Years.
If i recall they sometimes do some discounts on old content when they release new content. just a waiting game now. How patient is your Wallet....
Expected schedule for Steam sales this year: Steam Spring Sale 2020: Last week of May, although it's worth noting there wasn't one last year Steam Summer Sale 2020: Starts between June 20 and June 30, lasts for two weeks Steam Halloween Sale 2020: October 29 - November 1 Steam Autumn Sale 2020: Starts between November 20 and November 30, lasts for a week Steam Winter Sale 2020: December 17 - December 31