It's Hat of the
Month.
The hat is announced, made available, then obtainable all in a
month.
Not the hat is announced a few weeks in advanced, then made available, then obtainable in, totally to more than a month.
That is why.
It's like going to a store. They don't tell you that a product will be on sale/special next month.
Sure, game stores have release dates for games. So do we. It's the start of the month.
As I've said before, it has been confirmed by Pandora that hats will most certainly not be announced in advance.
Edit: It seems the post I was responding to was removed. o.o