Just How Many Days Does Bill Murray REALLY Spend Stuck Reliving Groundhog Day?

In case you didn't know, February 2nd is Groundhog Day. And to celebrate the momentous American holiday that inspired the bloody brilliant Bill Murray film of the same name, as well as the movie itself, we're going to answer one of the most asked questions in cinematic history:

Just how many days does Phil Connors spend trapped in the perpetual loop of Groundhog Day?

Okay, so director Harold Ramis has sort of already answered it on the DVD commentary of the film (10 years he reckoned) and then later, in response to several sites online running an article that came to an answer of just 8 years, 8 months, and 16 days, he offered the following (seemingly contradicting his own bloody answer in the process!):

I think the 10-year estimate is too short. It takes at least 10 years to get good at anything, and alloting for the down time and misguided years he spent, it had to be more like 30 or 40 years

Fair enough, Mr Ramis, but since when did I ever let something as trivial as the truth of the creator of something get in the way of a good opportunity to offer my own take? Anyway, I don't agree with his estimate at all, as you'll see below.

Now before I start, a small disclaimer - this article doesn't take into account days in which Phil does nothing (like those days when all you want to do is lie in bed and play with yourself - which he inevitably will have done), so don't go complaining that I haven't factored them in. I actually have, though not explicitly, because my calculation accepts that Phil may have spent time learning some of his new skills on the same day. Don't phone, it's just for fun!

This process will be broken up into handy stages, to help everyone to keep up. Right, so here goes...