date format validation

Validate a date in "YYYY-MM-DD" format.

function checkDateFormat($date)
{
    match the format of the date
    if (preg_match (\"^([0-9]{4})-([0-9]{2})-([0-9]{2})$\", $date, $parts))
    {
        check weather the date is valid of not
        if(checkdate($parts[2],$parts[3],$parts[1]))
            return true;
        else
        return false;
    }
    else
        return false;
}