1793304 - Monthly interval recurring event offset by one month

Status: RESOLVED DUPLICATE of bug 1789362

(Calendar :: Provider: CalDAV, defect)

Description

[r-a-y]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:105.0) Gecko/20100101 Firefox/105.0

Steps to reproduce:

I have a recurring event at the end of every third month on Google Calendar.

Here's the iCal for the event:

BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20160131T100000
DTEND;TZID=America/Los_Angeles:20160131T110000
RRULE:FREQ=MONTHLY;INTERVAL=3;BYMONTHDAY=-1
DTSTAMP:20221001T191948Z
UID:[e-mail]
CREATED:20160102T003148Z
DESCRIPTION:
LAST-MODIFIED:20220630T165033Z
LOCATION:
SEQUENCE:1
STATUS:CONFIRMED
SUMMARY:Every Three Months
TRANSP:OPAQUE
END:VEVENT

So this event should display every on:

• April 30
• July 31
• October 31
• January 31

I'm using the CalDAV Google Calendar URL to add the calendar to Thunderbird:

1. Added a "New Calendar" and selected "On the Network".
2. Next, I added a Google Calendar as a CalDAV URL for the "Location" field: https://apidata.googleusercontent.com/caldav/v2/CALENDARID/events

Actual results:

When the event is imported, the recurring event is offset by one month.

In Thunderbird. the recurring event is displaying every:

• March 31
• June 30
• September 30
• December 31

Expected results:

The recurring event should be the same as in Google Calendar.

Expected result is the recurring event should display every:

• April 30
• July 31
• October 31
• January 31

This bug could be related to 1791277.

Comment 1

[Martin Schröder [:mschroeder]]

For me this sounds like a duplicate of bug 1789362 which is not yet fixed in a Thunderbird 102 bugfix release.

Comment 2

[r-a-y]

Thanks Martin. I believe you are right.

I've already had several schedule-related problems due to this bug! So it would be great if the fix in bug 1789362 could be pushed to 102 branch as well.