Revealing mistake: Kate's birthday is July 10th. When she is (with long hair) outside on the patio with Alex, you can see their breath as they talk, and there is not a living thing in the back yard, it's all dormant (as in late fall/winter).
Revealing mistake: When Kate kisses Morgan in front of 1620 N. Racine, the camera moves up through the branches of a tree. You can see one of the lower branches shake when it is bumped by the crane. (01:17:20)
Answer: Kate asked him to wait, and come in 2008, so that's what he did. Likely they could have found each other before then, but it might not have even occurred to either of them.
They started communicating after he died in 2006 (her time) on his way to see her, but 2004 his time, neither of them knew he had died by this time so there was no way they could have met, my question is how did he know to go and meet her the first time if they hadn't started communicating yet?