Theory:Doctor Who television discontinuity and plot holes/Closing Time

The Doctor sees Amy and Rory in a shop on what must be April 20th two days before he is to die. At first glance, one must assume that this is the Amy and Rory from before the events of this season; after the events of The Big Bang, but before The Impossible Astronaut. We know that the pair hadn't heard from The Doctor for two months by that time - whether or not that means their wedding, or includes any later pops by to visit we don't know. So it's entirely possible enough time would have passed to invent and market a scent that has become popular enough to warrant getting her autograph. Small problem - the Amy from before the events of this season is not acquainted with the term Petrichor. If she was, she'd have recognized it when Idiris used it.

Now there's no issue with The Doctor going back a day or two to get the letters in the post in time for them to arrive a day or two ago. Heck, he got one to Canton in America, one to River on Stormcage and himself on the TARDIS, so that's scarcely a problem. However, by the 20th, Amy and Rory should have already gotten his letter and be heading off to meet him (as seen in The Impossible Astronaut). So they shouldn't even BE here. Best guess, this is the Amy and Rory from AFTER the recent series' events, who were brought back a fair period of time BEFORE they left for America, which may also explain why The Doctor bought them a new house and car; to keep themselves out of their own way.