I need to swap an image every Monday

[admin]

I need a script to swap an image every Monday. I have an image for every Monday of the year and would like an automatic alternative so I don't have to remember to switch it all the time.

I thought about using a naming convention on the image files like 20030428.gif and then parsing the filename and comparing it to today's date. But I haven't had any luck finding a way to parse the filename.

Any thoughts? Am I going about this the right way?

Thanks in advance.