Weekly quest stamp bug?
Answers
Well, either you've been playing fast and loose with the international date line, or the game forgot how to count. Should be 14,15,16,17,18,19. See what happens when you do another research task, and get the final box.
I guess all these quirky bugs is one of the joys of a major feature update. They will iron them out eventually, but for now we get some dubious behavior.
This kind of bug has been described before, only that guy got his second stamp of the day early, but subsequently did not get a stamp on the next day. In the end everything balanced out to a normal 7-days-7-stamps week. My guess is that the software assigns the wrong picture - your first "Jun 20" is in fact a "Jun 19" stamp, only the graphic is wrong. This happens all the time with photodiscs.
I've had this happen to me when I traveled from Europe to America, so what happened was I collected the stamp at around midnight in Europe and one day later I was in America. I think it might have gotten it confused with the time.
If you are one of the players who likes messing with the clock, I think that could cause this.