$year :
$month :
$day :
$utc :
__construct()
addDays( $days)
addMonths( $months)
addYears( $years)
timestamp()
toString( $fullformat = true)
__toString()
isLeapYear( $year)
daysInMonth( $year, $month)
isValidDate( $year, $month, $day)
dayOfWeek()
dayOfYear()
