/**
* @param integer $dayOfYear The day-of-year to check, validated as an integer.
* @param integer|null $year An optional year to check against, fully validated.
*
* @return void
*
* @throws DateTimeException If the day-of-year is not valid.
*/
public static function check($dayOfYear, $year = null)
{
if ($dayOfYear < 1 || $dayOfYear > 366) {
throw DateTimeException::fieldNotInRange(self::NAME, $dayOfYear, 1, 366);
}
if ($dayOfYear === 366 && $year !== null) {
if (!Year::isLeap($year)) {
throw new DateTimeException("Invalid day-of-year 366 as {$year} is not a leap year");
}
}
}
/**
* Returns the length of the given month-of-year.
*
* If no year is given, the highest value (29) is returned for the month of February.
*
* @param integer $monthOfYear The month-of-year, fully validated.
* @param integer|null $year An optional year the month-of-year belongs to, fully validated.
*
* @return integer
*/
public static function getLength($monthOfYear, $year = null)
{
switch ($monthOfYear) {
case 2:
return $year === null || Year::isLeap($year) ? 29 : 28;
case 4:
case 6:
case 9:
case 11:
return 30;
default:
return 31;
}
}
/**
* Checks if the year is a leap year, according to the ISO proleptic calendar system rules.
*
* @return boolean
*/
public function isLeapYear()
{
return Field\Year::isLeap($this->year);
}
/**
* Returns a copy of this YearMonth with the year altered.
*
* @param integer $year
*
* @return YearMonth
*/
public function withYear($year)
{
$year = Cast::toInteger($year);
if ($year === $this->year) {
return $this;
}
Field\Year::check($year);
return new YearMonth($year, $this->month);
}
/**
* Returns whether the given year is valid for this month-day.
*
* This method checks whether this month and day and the input year form a valid date.
* This can only return false for February 29th.
*
* @param integer $year
*
* @return boolean
*/
public function isValidYear($year)
{
return $this->month !== 2 || $this->day !== 29 || Field\Year::isLeap($year);
}
/**
* Returns a copy of this year with the specified number of years subtracted.
*
* This instance is immutable and unaffected by this method call.
*
* @param integer $years The years to subtract, may be negative.
*
* @return Year A Year based on this year with the period subtracted.
*
* @throws DateTimeException If the resulting year exceeds the supported range.
*/
public function minus($years)
{
$years = Cast::toInteger($years);
if ($years === 0) {
return $this;
}
$year = $this->year - $years;
Field\Year::check($year);
return new Year($year);
}
