I once seen a video on YouTube before which I believe first came up with this theory, but I can’t find it. Anyway, the theory is that the Doctor is going up and down Amy and Rory’s time-stream back and forth, and there is a few things which could potentially support it:
The Doctor, the Widow and the Wardrobe:
As with the rule that the Christmas special takes place in the same year as the series before if it takes place in the 21st century unless directly stated (Planet of the Dead onwards). The present day episodes of Series 6 takes place in 2011, March-April, but Amy says it’s been 2 years, meaning it’s either 2012 or 2013, 2012 as a rounding up by Amy, or 2 years and she’s rounding down. Since The Angels Take Manhattan takes place in 2012, unless the Doctor has taken Amy and Rory from the future to 2012, this potentially shows that the Doctor is going up and down Amy and Rory’s timeline.
Dinosaurs on a Spaceship:
When Rory says he doesn’t have a Christmas list anymore after talking to his dad, he says that he’s 31. The wiki states that he was born in 1989, which unless they are aging differently due to being on the TARDIS as they were full-time companions, this is personally stating that it takes place in 2020 when the Doctor materialises around Amy, Rory and Brian.
The Power of Three:
At one point in the episode, Amy says “You think it’s been ten years. Not for you, or for Earth, but for us, ten years for us of you. On and off.” The part I’m interested in is on and off. We know that they left the TARDIS the first time in The God Complex but after that they stayed as part-time companions till the end of this episode, since they were on and off, the Doctor could have potentially visited them in the wrong order, Dinosaurs has to take place after Asylum as they mention the divorce but Town could take place anywhere between Pond Life 1 and Asylum but Power of Three directly shows us a follow up to a mention in A Town Called in Mercy implying that part takes place not too long after.
Pond Life 2 (May):
This actually shows us that this is happening, as the Doctor materialises the TARDIS in Amy and Rory’s seemingly trying to recruit them to stop the spaceship that’s hurtling towards Earth in Dinosaurs on a Spaceship, but he says that he’s too early and heads off again. This actually tells us that the Doctor is tiring up in the wrong order, but the Doctor tells us that this is completely accidental as there the helmic regulators aren’t working but part of the theory is that it isn’t completely accidentally or even intentionally but this shows us otherwise.
I don’t know if the theory on the YouTube video I saw said this or not, this was technically a way to save Amy and Rory from the Angels zapping them back in time as he could just say this to the past selves of Amy and Rory, but it would either create a paradox or an alternate timeline, but the Doctor doesn’t want to disrupt time, but another part of this which may or may not be my addition is that the Doctor went to an earlier version of Rory and Amy and said that he can’t travel with them, but they’ll travel with him and see him soon, but he won’t give any details as to why, as he doesn’t want to disrupt time and that he respects Amy’s decision to stay with Rory in 1930’s New York even though there is a way out, as even if he creates another alternate timeline in which they survive, that timelines Amy and Rory would still be dead and that when he did this was before or after The Bells of Saint John prequel as he is wearing clothes very similar to one which he wore when he travelled with Rory and Amy and that he was wearing the purple coats with Clara.
Please tell me what you guys personally think about this theory!