[RESOLVED] Date Math: Tutorial Out There?

[mrhinman]

I'm looking for a tutorial on doing date math in PHP.

Specifically, I need to be able to add or subtract days and be sure the month and year get changed where appropriate.

Example:
2006-04-05 MINUS 7 days = 2006-03-31
2006-12-26 PLUS 7 days = 2007-01-01
etc.

I'm having difficulty coiming up with a simple way to do it without screwing up my table data which is stored as YYYY-MM-DD.

[mrhinman]

SOLVED:

$day2 = date("Y-m-d", strtotime("-1 day"));
$day3 = date("Y-m-d", strtotime("-2 days"));
$day4 = date("Y-m-d", strtotime("-3 days"));
$day5 = date("Y-m-d", strtotime("-4 days"));
$day6 = date("Y-m-d", strtotime("-5 days"));
$day7 = date("Y-m-d", strtotime("-6 days"));