fix: refactor advanceTheDate

lib/Recur/RRuleIterator.php

@@ -286,29 +286,16 @@ public function fastForward(\DateTimeInterface $dt): void
 
  /**
  * Advances currentDate by the interval.
- * Takes into account the case where summer time starts and
- * the event time on that day may have had to be advanced,
- * usually by 1 hour.
+ * The time is set from the original startDate.
+ * If the recurrence is on a day when summer time started, then the
+ * time on that day may have jumped forward, for example, from 0230 to 0330.
+ * Using the original time means that the next recurrence will be calculated
+ * based on the original start time and the day/week/month/year interval.
+ * So the start time of the next occurrence can correctly revert to 0230.
  */
  protected function advanceTheDate(string $interval): void
  {
- $hourOfPreviousDate = (int) $this->currentDate->format('G');
- $this->currentDate = $this->currentDate->modify($interval);
- if (0 === $this->hourJump) {
- // Remember if the clock time jumped forward on the next date.
- // That happens if the next date is a day when summer time starts
- // and the event time is in the non-existent hour of the day.
- // For example, an event that normally starts at 02:30 will
- // have to start at 03:30 on that day.
- $hourOfNextDate = (int) $this->currentDate->format('G');
- $this->hourJump = $hourOfNextDate - $hourOfPreviousDate;
- } else {
- // The hour "jumped" for the previous date, to avoid the non-existent time.
- // currentDate got set ahead by (usually) 1 hour on that day.
- // Adjust it back for this next occurrence.
- $this->currentDate = $this->currentDate->sub(new \DateInterval('PT'.$this->hourJump.'H'));
- $this->hourJump = 0;
- }
+ $this->currentDate = $this->currentDate->modify($interval.' '.$this->startDate->format('H:i:s'));
  }
 
  /**