Every Steam sale and event coming in 2023 has been revealed

pcgamer.com:

Remember when predicting (guessing) the big Steam sale dates was basically a national pastime? It seems so long ago, and frankly a little bit weird in hindsight. (It was also very stressful for those of us tasked with writing Steam sale announcement news.) Now, though, we can plan our whole year in advance, because Valve has revealed the dates for every Steam sale and fest coming in 2023(opens in new tab).

Valve changed its Steam sale structure(opens in new tab) in September 2022, cutting the Lunar New Year sale from its schedule in favor of a more evenly spaced seasonal schedule. The reasoning was simple: Lunar New Year sales typically dropped just a few weeks after the wallet-demolishing Winter sales, and it was just too much Steam sale in too little time. 

But then Valve hit us with a Chinese New Year sale(opens in new tab) instead, a slightly scaled-down event that kept the deal train running. And it's not letting up: Between the big seasonal events, the Steam Next Fests—three of them—and various themed fests popping up throughout the year, the remainder of 2023 isn't going to go any easier on your bank balance.

Here's what's coming through the year—aside from the Mystery Fest, which is currently underway, the links don't lead to sale pages but to Steamworks documentation for developers who want to take part:

At a glance, it looks like the longest «no Steam sale» stretch we're going to get in 2023 is a month, between the end of the Spring sale on March 23 and the start of the Puzzle Fest on April 24. By contrast, the shortest break is just three days, from the end of the Next Fest on June 26 to the start of the Summer sale on June 29. For the most part, you'll get at least a week or two between sales—not enough time