find date that was 30 days ago.

[firman]

If I have a value of 2006-04-06 and I wanted to find out what 30 or 60 or 73 or whatever many days before that was... How would I write that code?

[ellisgl]

Convert the date to a time stamp.
$stamp = mktime(0,0,0,$mon,$day,$year);

Figure out how many seconds to subtract from.
$a = 86400*$days;

$b = $stamp - $a;

Then convert the time stamp with date
$c = date ( "Y-m-d", $b);

[NogDog]

$date = '2006-04-06';
$thirtyDaysAgo = strtotime('-30 days', strtotime($date));