Valve never do manage to keep sale dates hidden for long, but for the dates of the three next major sales to slip is a bit embarrassing. Not really much they can do about it though, unless they want to hide the dates from developers for longer, or restrict who is able to actually see them.

Here's the dates:

Steam Halloween Sale: October 26th 2017 - November 1st 2017

Steam Autumn Sale: November 22nd 2017 - November 28th 2017

Steam Winter Sale: December 21st 2017 - January 4th 2018

Each sale will apparently start around 6PM UK time and end around the same time on each date, so keep that in mind.

Looks like Observer from Aspyr Media and Bloober Team, will make it just in time for the Halloween sale! I'm very excited for that one.

What are you planning on picking up over the next few sales?

Source, Kotaku.