When is a good time to create a late property tax list?

[Jon K.]

I'm working on a direct mail list using unpaid property taxes and It occurs to me that in the area in which I am searching they don't assess a late fee until the calendar year ends. For those who have experience with this, should I just wait for say mid January to put effort into this sort of list? I feel like a late tax bill holds more weight once it's truly "late".