Five real Steam front pages a day. Date each to the month.
Each day has five of Steam's real front pages, the same five for everyone. Move the dial to the month you think each one is from and lock it in. A page dated to the month scores 1,000; a year out scores about 550, and four years out under 100. The best day is 5,000.
From the Internet Archive's Wayback Machine, which has captured Steam's front page almost every month since October 2003: steampowered.com until autumn 2008, then store.steampowered.com. They are the same captures as the Steam time machine, which has every month to look around in.
The games being sold and their prices, the sales running that month, and how the store itself looked. Tap a page to look closer. A few old pages printed the day a game came out; those lines are blurred, since they would give the answer away.
Every day at midnight, your time. No page comes back until every other month has been played.
Pages archived by the Internet Archive's Wayback Machine; every month is in the Steam time machine. Steam and the Steam logo are trademarks of Valve Corporation; this site is not affiliated with Valve.