Please correct me if I am using the rrule plugin incorrectly.

FullCalendar Version 6.1.11 with rrule plugin in React

The below pertains to recurring events only. I do not have the issue with normal events.

codepen: https://codepen.io/tcjens/pen/XWwbvQL?editors=001

     {
       title: 'rrule event',
        rrule: {
          dtstart: '2024-05-17T06:00:00.000Z', //2am Fridays EDT or 11PM Thursdays PDT
          freq: 'weekly',
          byweekday:['fr']
        },
        duration: '01:00'
      }

My backend stores all dates in UTC

Im on an air-gapped network. I am not able to share my code. But it’s replicated in reduced form in the code pen.

Perhaps this is user error – but any help is highly appreciated!!!

When setting dtstart of an RRule for an event to an ISOString() formatted string with timezone, DST is not respected accross the OCT 31 / NOV 1 barrier as seen in the code pen. However differences in the ‘byweekday’ array accross timezones are still respected.

For example, a recurring event at 2AM on Fridays EDT is actually 11PM Thursdays PDT. When using ISOString() dtstart, this difference is observed, but not DST accross OCT31/NOV1

However, if you set dtstart without a timezone, DST is observed and reflected BUT the weekdays will not be adjusted according to timezone.