UPDATE

GOG locked an old thread that no one touched for one month.
https://www.gog.com/forum/general/list_of_drmfree_video_games_digital_distributors

The thread is over 4 years old.
The thread helped a lot of people to find DRM-free stores.
GOG just punished me because I hope them let Russians and Belarusians buy DRM-free games.
Fuck you GOG. I will never spend any money here.

And I will stop to update my threads.

After a quick search, there are GOG's recent time-related bugs that I found.
Note: GOG have much much more this kind of bugs. I just have not searched them all yet.

Jun 2017
Promo: Nex Machina
Bug: countdown clock stopped 8 days earlier

1 Aug 2017
Promo: Runic Games Collection
Bug: wrong end-date announcement, and bug fixed very late

28 Aug 2017
Promo: Weekly Sale: Square Enix
Bug: countdown clock wrong

4 Sep 2017
Promo: Weekly Sale
Bug: countdown clock wrong

25 Sep 2017
Promo: Weekly Sale: Daedalic and Night Dive treasures
Bug: both countdown clocks are wrong, and mismatch to each other

Oct 2017
Promo: Starpoint Gemini Warlords - Cycle of Warfare
Bug: countdown clock at least 58 hours shorter

9 Oct 2017
Promo: WEEKLY SALE: 2K GAMES + PARADOX + REBELLION UP TO -75%
Bug: countdown clock stopped 7 days earlier at homepage

What for? We all know GOG does a lot of mistakes/bugs/screw-ups of this sort. Kicking a man when he's down?

If you have to pay this man, you will want to kick him.

If the man always down like this, I will hire another man to replace him.
(In fact, I buy more and more at Humble Bundle, because GOG is tooooooo buggy for me.)

Sure, I get and respect that part about not trusting/not wanting to deal with a sloppy seller. But why do you make a list about errors in promo durations? What's the purpose? There are some lists around here that have a good purpose:
- Missing manuals -> not only you can get info where to find them but in some cases you may learn that some games never had one.
- Regional priced games -> It may help people who are strictly against the idea of regional pricing so that they can avoid games that are affected.
etc.

Your list? Seems to be "OMG, GOG is SOOO sloppy, I'll make fun of them, LOL" type of list. But maybe I'm too blind to see something and hence the question.

My good list for GOG:
https://www.gog.com/forum/general/gog_buy_series_discount_list
https://www.gog.com/forum/general/bonus_games_included_in_gog_games
https://www.gog.com/forum/general/rom_based_gog_games_compatible_with_third_party_emulators_thread
https://www.gog.com/forum/general/list_of_gog_games_on_humble_bundle

Not my list, but I am very active:
https://www.gog.com/forum/general/the_unannounced_gog_promo_thread

In fact, bug reporting is GOOD for GOG.
So I think this thread you are reading is positive for GOG overall.

UPDATE
Fix a wrong URL.

I always appreciated your lists but the fact that you've started/contributed to a lot of good lists does not make this one any better. Promo duration bugs have been reported on the spot and I seriously doubt that keeping a list about them will change/help anything. But maybe, I'm really too blind for this so I won't bother you any further. Have a nice time :)

Oct 2017
Promo: WAR FOR THE OVERWORLD UP TO -72%
Bug: the promo is still 8 days left, but is not visible at homepage. New GOG member will very hard to notice this promo.

16 Oct 2017
Promo: The Witcher series
Bug: both countdown clocks are wrong, and mismatch to each other

After first "fix", both clocks matched to each other, but they are still wrong.

GOG staff's ability is really really doubtful.

Sep 14 2017
Promo: immature leakage of The BIG DEAL Sale (18-25 Sep)
Bug: the immature promo appear 4 days earlier, and only lasts for hours. Over 300 games were discounted during that time span.

I'm kind puzzled myself, as the other user above, about the exact purpose of this....
You think a two lines "bug report" (if we really wanna call it that way) like this one above, of a promo happened a month ago, will actually be of any use in tracking some bug in the code, if it ever existed in the first place?! (and it's not simply an operator mistake)

And even assuming this report actually contained any useful info for tracking the problem, why don't you submit that directly to the support, instead of opening a forum topic?!

I have submitted GOG Support tickets, but their response is damn slow.
Even after I start this thread, GOG still set clock wrong repeatly, and the bug for The Witcher promo is not fixed yet.

GOG just do not care their quality, and do not care the wrong clock.
I am free to record those bugs here, and you are free to ignore me.

And this list is supposed to change that... how exactly? (O.o)
Fair enough, carry on then.
I've seen less useful lists on the forum so this is... OK, I guess.

23 Oct 2017
Promo: WEEKLY SALE: TEAM 17 UP TO -90%
Bug: countdown clock wrong