DEAN: There must be some other excuse that you could use.
RORY: Like what?
DEAN: Like it’s your three-month anniversary with your boyfriend.
RORY: It is?
DEAN: Yeah. Three months from your birthday. I mean, that’s when I gave you the bracelet and that’s when I figured this whole thing kinda started.
RORY: Wow. Three months.
DEAN: Actually, technically your birthday was on a Saturday, so really it should be Saturday, but I work Saturday and I planned out this whole big thing so I thought maybe we could do it on Friday.
There is no way that we are only three months from the night that Dean gave Rory her bracelet as a birthday present (despite what Dean says, it wasn’t her birthday, but the day after her birthday). That was in late October, so three months later would be late January. It’s now mid-March, so it’s roughly four and a half months from her birthday.
Frustratingly, it is about three months after another significant date in their relationship – the night of the Chilton Winter Formal on December 9, when Dean and Rory mutually agreed that they were boyfriend and girlfriend. It would have made a lot more sense if Dean decided that was the start of their relationship, and then we could have dated their anniversary dinner to March 9.
Dean says technically it should have held on the Saturday as Rory’s birthday was a Saturday (again, not her birthday, but her birthday party in Stars Hollow), but he has to work that night. That isn’t how anniversaries work – they are on the same date each time, not on the same day of the week. This one is just really perplexing. (It also shows that if there is any clash in their schedules, Dean expects Rory to change her schedule to suit him, rather than changing his schedule for her).
We’re probably meant to be struck by how much more invested in the relationship Dean is than Rory, as she paid no attention to the one-month and two-month anniversaries while he did. However, due to this sloppy and confusing writing, you can hardly hardly blame her for that.
Dean has arbitrarily decided what marks the start of their relationship, and has his own method of deciding what makes a month. Under these circumstances, any normal person would have been at a loss to keep up. Of course, it does show that Rory just hasn’t been paying attention to her relationship and is taking it for granted.