Update: Reddit thread creator Quantumbinman just forwarded me PayPal Japan's email, and it's entirely legit—and mirrored on a PayPal domain. It's official! The Steam sale is exactly one week away!
Original: PayPal have allegedly done it again. Still heady from leaking the start date of last month's Autumn sale, PayPal Japan has seemingly emailed a Reddit user the date of the Winter Sale. It's December 18th, based on the image linked in this here thread.
To be clear, this is unconfirmed. The PayPal early warning system has been a long-standing and reliable indicator of an imminent Steam Sale. But also, I don't get email alerts from PayPal Japan, so can't exactly verify that the screenshot snapshot is real.
Here's the thing, though: I suspect it might be. Last year, the sale landed on the 19th—the Thursday before Christmas week. This year, that day falls on the 18th. Common sense says that yes, that's probably the one.
But, there's also this: December 18th is the release date of Metal Gear Solid V: Ground Zeroes, and new games aren't traditionally released during the sale period.
Should you care, only a few weeks after the Autumn Sale? Maybe. The Winter Sale is both longer and bigger, and while many of the Daily Deal discounts will be the same, more games will make it into the featured slots. And they'll probably do something weird with meta-challenges and trading cards and rare collectibles for free-to-play titles, if you're into that.