subtracting Dates

Hello, I am trying to make a hit counter graph that will have 7 days to it. Monday thru Friday. I'm having problems getting the last 7 days. For instance today is 05-01-2001 I would like to determan the previous 7 days from that date. In VB Date - 7 = 04-24-2001 I would like this to work for any date using php. Here is what I have so far... $t = (date ("m-d-Y")); echo $t; // output 05-01-2001 echo "<br>"; $r = $t - 7; echo $r; //output -2 but now $r returns -2 How do I get $r to yesterdays date in this format. 04-30-2001 Thank you --Mike __________________________________________________ Do You Yahoo!? Yahoo! Auctions - buy the things you want at great prices http://auctions.yahoo.com/