years between 2 dates

[Anon]

Hi,

I try to setup something that calsulates the number of years between to dates.

I tried somthing with the strtotime function:
$date1 = strtotime ("11 October 2001");
$date2 = strtotime ("15 October 2000");
$years = floor(($date2 - $date1)/(3652460*60));

but I can't figure out how to deal with leap-years?

Any ideas how to do this?

Thanks,
Raoul