1949465 - calendar events disappearing vanishing not existing any more

Status: UNCONFIRMED

(Calendar :: General, defect)

Description

[abittner]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:128.0) Gecko/20100101 Firefox/128.0

Steps to reproduce:

I recreated the calendar events (multiple) for example family birthdays anniversaries using tht exact dates of tens of years and many decades in the past so the actual old and anicent years for the anniversary and birthday being exact for example. I scroll back in the little calendar popup/applet popup and select the year many decades back and enter the calendar event there in the original year, select birthday or anniversary for example, select yearly recurring and select a reminder of few days or a week, all pretty normal, all local calendar.

just today after starting up my thunderbird on opensuse leap 15.6, x64, native opensuse build/rpm of mozilla thunderbird all normal installations via zypper, repos etc..

currently being:

Name : MozillaThunderbird
Version : 128.7.0
Release : 150200.8.200.1
Architecture: x86_64
Install Date: Mon Feb 10 16:43:16 2025
Group : Productivity/Networking/Email/Clients
Size : 271376078
License : MPL-2.0
Signature : RSA/SHA256, Thu Feb 6 20:46:03 2025, Key ID 70af9e8139db7c82
Source RPM : MozillaThunderbird-128.7.0-150200.8.200.1.src.rpm

I visit the local calendar tab and I see two birthdays for example gone again, two events that I just recreated some days ago. they are completely gone.

I have created a test event for tomorrow having an original native date (year) in the same decade as those two vanished events just to make sure, maybe this got to do something with UNIX time? not existing before 1970? or something is in the back of my head? is this maybe possible?

events have multiple times vanished from this mozilla thunderbird on opensuse and in the past weeks I have noticed this behavior and observed, and I was very much confused as I even see the missing anniversary/birthday event in the raw exported .ics file I have saved here and transported over to this linux system from previously the windows/32bit system, and in the .ics the event(s) is still listed in there visible as text lines etc (.ics )

I have never had missing or disappearing or vanishing calendar events on windows in the past and I use a number of events that have really old dates set from their original situation in ancient decades.

Actual results:

long time user have been on 32bit windows (xp) with thunderbird
some while back I exported all my calendar (local) events into .ics file with the windows 32bit thunderbird version and imported into opensuse thunderbird version. all seemed fine. after a while I observed that calendar events obvious and well known to me such as e.g. family anniversaries completely disappear, vanish, from the days they ought to be on and also from the global list of events all the same. I dont find searching for the special names and text that they constist of.

Expected results:

events to stay and not disappear?

Comment 1

[abittner]

so I have that test event set for coming up tomorrow, will quit thunderbird later today and restart thunderbird tomorrow and see if that even is gone as well the same way. this UNIX time stuff is kind of the only thing that I can come up with, why stuff would vanish, is this possible at all?

I am really dumbfounded as this is such an essential bug and i can not understand how you would be able to use a calendar software with vanishing objects from it.

thanks for help and debugging.

Comment 2

[abittner]

I only re-started thunderbird today ( I explicitly start it by: /usr/bin/thunderbird -ProfileManager & )

and three calendar entries vanished again, I have screenshot as delta. I only started thunderbird, and changed into the calendar tab and I see the losses (missing places) there, other events are still there.

these calendar events contain no other specialties that I can think of, no exotic stuff, only the year is many decades in the past.

the one calendar event which was only my debugging test event on february 21st (this event never existed before at all, was only created a few days ago as I have described in this bug report, is not a real event only for testing and doesnt exist in the .ics export back from the windows thunderbird days) with the original year many decades ago vanished just as well, as well as two birthdays from the family in february as well also with very old years set.

so this is pretty much a huge data loss to the user :(

Comment 3

[abittner]

and I have discovered that a birthday belonging to february now lists in january and the date itself is even being in the wrong moth, 6 days off within the month and going back to earlier decades of the past century. very odd. the entry itself seems proper and with my comments on the birthday and even inside the comments the proper date is listed as text.

odd.

Comment 4

[abittner]

this one event that teleported over to january and the wrong day within the month also had an original year of the 1950s but then when edit all occurrences, it listed years going way back into the 1920s and 1930s etc....

is it maybe possible that something is amiss of the handling of an operating systems date/time settings and locale and interpretation of two digit and four digit years and months and what not related calculations or representations or so?

i find it hard to believe that such bugs exist in the calendar base

then again, this one new event for debugging was only being added on this opensuse linux thunderbird and on this single machine and not exported or transported over from/to windows and has never left this machine etc, and never the less even this brand new event vanished into thin air and disappeared.

thanks.