juicy, ty!

Doom Eternal? Not sure of the date

Doom Eternal as Shanti said, listed by the OP here:
https://www.steamgifts.com/discussion/1sBDP/humble-adding-expiration-dates-without-notice
+some others listed by some users in the Reddit thread OP linked, and some by wigglenose in the SG thread.

Friends vs Friends - Must be redeemed by December 3rd, 2024 by 11:59 PM Pacific Time.
source

(some are already expired, shown with a strikethrough)

(Source: data gathered from Barter, if you visit each bundle page, you'll see a table of games with a little icon ⏰ for games with expiration date)

Updated main post. I adopted the table style of ormax3's post for the most part, but I changed the order a bit and double-checked some dates.

In case anyone will be buying keys from resellers this is a topic to follow

Expecting massive discounts as the end date approaches

Already visible with Deathloop

Edit: Would be nice if you could sort it by end date

Solid resource.

Thanks. I didn’t even realize some of them expire like that. Looks like my Command & Conquer Remastered Collection key expired. :(

Thanks, looks like I'll need to get rid of that Doom Eternal key fast :x

It might be useful to also add a "publisher" column to the table so that we know which ones are likely to do the same in the future?

Helpful!
Grateful bump

On Barter, you can see all the items with the "activation deadline" tag here: https://barter.vg/notices/402
The list there could be improved by adding the actual deadline, and the platform (as they're mixed Steam / GOG / Epic items). Unfortunately I don't think there are enough resources to implement these changes at the moment, but at least you can see easily everything that gets tracked.

Notices about future expiry dates are also posted in the appropriate channel on the Barter Discord, but it's difficult to see them as that channel gathers all notification types, not only the activation deadlines. This is how it looks like:
https://i.imgur.com/vcUNRPP.png

Same as Disjunction, Encodya (GOG key) from August 2021 Humble Choice have a expiration date on 2031-07-28

Fallout 76 code for me expires February 29th. Fallout 1 is the correct date of March 5th.