I fully agree that Moffat won't care and 99% of the audience won't notice but there's no getting away from the fact that there's been more definite on-screen dating for the Amy-Rory years (and for the number of years that pass after they stop traveling full-time) than for any other "present-day" period in the series history.
Rory was born in 1989 and says he is 31 in DOAS, which puts it in 2020. TPO3 takes place after it which makes that year the earliest real date that the Doctor meets Kate.
Here's the Craig Hinton Memorial Fanwank Explanation: In an unseen story that takes place before this one where Kate meets the Doctor for the first time from her POV he tells her that when they meet in 2020 she should act like it's the first time as it will be from his POV. (As happens in a 6th Doctor Big Finish audio whose name escape me at the moment.)
Then how come Kate doesn't appear to age much between 2013 (DOTD) and TPOT (2020)?
I'm personally not all that convinced Kate was lying in TPOT; I reckon she genuinely hadn't met Eleven before then. But then we also know that history can be changed. Perhaps in a subsequent adventure, the Doctor went back in time and met Kate earlier in her personal timeline, explaining how she might recognize him in DOTD?