/**
* Calculates the period between this date and another date.
*
* This calculates the period between the two dates in terms of years, months and days.
* The result will be negative if the end is before the start.
* The negative sign will be the same in each of year, month and day.
*
* The start date is included, but the end date is not.
* The period is calculated by removing complete months, then calculating
* the remaining number of days, adjusting to ensure that both have the same sign.
* The number of months is then normalized into years and months based on a 12 month year.
* A month is considered to be complete if the end day-of-month is greater
* than or equal to the start day-of-month.
*
* For example, from `2010-01-15` to `2011-03-18` is 1 year, 2 months and 3 days.
*
* @param LocalDate $endDateExclusive
*
* @return Period
*/
public function until(LocalDate $endDateExclusive)
{
$totalMonths = $endDateExclusive->getProlepticMonth() - $this->getProlepticMonth();
$days = $endDateExclusive->day - $this->day;
if ($totalMonths > 0 && $days < 0) {
$totalMonths--;
$calcDate = $this->plusMonths($totalMonths);
$days = $endDateExclusive->toEpochDay() - $calcDate->toEpochDay();
} elseif ($totalMonths < 0 && $days > 0) {
$totalMonths++;
$days -= $endDateExclusive->getLengthOfMonth();
}
$years = intdiv($totalMonths, 12);
$months = $totalMonths % 12;
return Period::of($years, $months, $days);
}