Although there is no exact information on exactly when this discount period begins, there is a leak on the internet that claims to get this data from the Steamworks developer group.
As the post is announced in Reddit, there is news that Steam Summer Sale 2017 will be held on June 22 - July 5, 2017.
For comparison, in the year 2016, Summer Sale held on June 23 - July 4, 2016. Therefore, if the above leak was misplaced, certainly not be much different from the calendar.
Steam Summer Sale to be one of the most appropriate moments to buy some interesting games that gamers want with great discounts.
True or not the date, the most important now is, have gamers prepare their wallets to face the onslaught of Steam this time?