These promotions should start on the 25th of June, Wednesday, around 6 p.m. The end of the promotions is scheduled for July 9th.
Steam sales occur at regular times of the year. By looking back at Steam sale dates from the last few years we can guess approximate dates for 2020.
Until the sale itself is launched, it’s hard to say which games will be discounted. But in recent years, some surprisingly big and recently released titles have seen their prices cut.