gform_date_min_year not working

I have used this documentation to modify the date fields on a form:
http://www.gravityhelp.com/documentation/page/Gform_date_min_year

So I have put this in my functions.php file but it does not change the minimum year from the selection list to 2012. It still shows years back to 1912:

// Date fields on forms will be looking for a date going foward. So make the minimum year the
// the current one.
add_filter("gform_date_min_year", "set_min_year");
function set_min_year($min_year){
	return intval(date("Y"));
}

Any thoughts on why this might not be working?