As I said on the sister thread to this one, about Captain Marvel's anniversary, the 75th anniversary was actually in 2014 for Cap, Flash, Hawkman and Johnny Thunder. I guess the mistake arises because of the cover dates which were 1940--but if you check the
Newsstand on Mike's Amazing World, you can see when these books actually came out on sale.
ALL-STAR COMICS No. 3 (Winter '40-'41) did come out on November 22nd, 1940, so it makes sense to celebrate that 75th anniversary in this year--even though using the cover date you could celebrate it in 2016 [Mike's gives the date as Winder 1940, but the GCD gives it as Winter 1940-41 and I think the latter is more accurate given the GCD uses the indicia date]. Since FLASH COMICS No. 1 (January '40) came out on November 10th, 1939, it doesn't seem right to celebrate both anniversaries in the same year since they're more than a year apart. It would be like trying to eat your cake and have it, too. Pick a criteria for anniversaries and stick with that.
Personally, I would have rather celebrated the anniversaries of the Flash, Hawkman and Captain Marvel around Thanksgiving and Christmas in the spirit of the season.
All of this might seem like picky little details to you--but to someone like me this kind of stuff is much more exciting than all those discussions on whether the Hulk could beat up Superman.