Also, if you know the format is consistent, you might consider using [man]mktime/man to explicitly state the numerical values for the month/day/etc. Here's an example why this might be best:
echo date("M", strtotime("02-03-2009")); // Mar
echo date("M", strtotime("02/03/2009")); // Feb
echo date("M", strtotime("02.03.2009")); // Mar