There are different ways to check that...
If you use a timestamp to store your dates, you can do something like this:
// Current date - 60 days...
$min = time() - 60 60 24 * 60;
SELECT * FROM table WHERE date >= $min
Or... when you use mysql date or datetime field, you can do it this way:
SELECT * FROM table WHERE date >= DATE_SUB(date, INTERVAL 60 DAY)
Hope it helps...
Greetz,
Daniel