Current month change

Hello,

Total n00b here who needs help. I have a list of weblog (blog) entries in a
database which are being retrieved by index.php with a string of $mid=9
where'9' is the current month. Is there a way of automatically retrieving
the entries depending on what month we are in, so that when users go to my
website they automatically see the current months entries which
automatically changes as the month changes?

Many thanks.

sipz