1071354 - when trying to set start time and/or end time to 02:00AM, time(s) keep resetting to 03:00AM

Status: UNCONFIRMED

(Calendar :: Alarms, defect)

Description

[ssafmea]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:32.0) Gecko/20100101 Firefox/32.0
Build ID: 20140917194002

Steps to reproduce:

I tried to set event reminders to remind when standard time and daylight saving time occur. Here in Canada, Standard Time begins on 1st Sunday in November at 02:00AM and Daylight Saving Time begins on 2nd Sunday in March at 02:00AM, times being in local time zone and in the current season (e.g. if already on Eastern Standard Time, then Daylight Saving Time begins on 2nd Sunday in March at 02:00AM Eastern Standard Time. If reverting back to Standard Time from Daylight Saving Time, the change occurs on 1st Sunday in November at 02:00AM  Eastern Daylight Time.


Standard Time Reminder:

I first created an event to remind me when Standard Time begins by pointing the calendar to November 2014, then selecting November 2nd (i.e. first Sunday in November, 2014). I then set the event Start Time to 02:00. I then advanced the calendar to March, 2015 and selected date of March 8th (2nd Sunday in March) for End Time of Standard Time (which is the beginning of Daylight Saving Time). Results explained in next window, below under "Standard Time Reminder". (I should point out that I already had an existing reminder for Daylight Saving Time that I had created last spring/winter, but I don't believe this makes any difference to the problem described here).


Daylight Saving Time Reminder:

I also tried to create a second reminder for when Daylight Saving Time begins by pointing the calendar to March 8th, 2015, and creating a new event, setting the Start Time to 02:00AM and the End Date/Time to November 1st, 2015. Results explained in next window under "Daylight Saving Time Reminder".







Actual results:

Standard Time Reminder:

When I tried to set the Standard Time reminder End Time to 02:00AM, it kept/keeps changing to 03:00AM. If I set the end time to 01:59AM, the time remains set to 01:59AM. It appears if the end time is set to anything between 02:00 to 02:59, the time keeps changing to an hour ahead.


Daylight Saving Time Reminder:

When I set the Daylight Saving Time reminder event Start Time to 02:00AM, it immediately changed to 03:00AM. If I set the Start Time to 01:59AM, then the time remains set at 01:59. I can then set the event End Date/Time to November 1st, 2015, 02:00AM. However, after saving the event, if I later come back and try changing the Daylight Saving Time to 02:00AM (from 01:59AM), then the Start Time again changes to 03:00AM and the End Time, too, changes, to 03:01AM (!?).



Expected results:

I expected that when I set the Standard Time event/reminder End Time to 02:00AM, it would show "02:00" and not change to something else (i.e. 03:00 as happened).

I expected that when I set the Daylight Saving Time event/reminder Start and End times to 02:00 (using different dates for each time), they would both show 02:00 and not change to something else (i.e. to 03:00 and/or 03:01 as happened).

I first thought that perhaps my trying to have two separate events whose start/end dates/times coincide, might be corrupting the start and/or end times of one or both events, however, I obtained the same results described above for the Standard Time reminder, even after I deleted the event reminder for Daylight Saving Time.

I then wondered if somehow Lightning Calendar is already taking the change to Daylight Saving Time into account by advancing the end time an hour to 03:00AM when I initially set it to 02:00AM. If so, this seems strange, given that Thunderbird doesn't have it's own clock, but uses the computer system clock and the system clock is currently still set to Daylight Saving Time when I am trying to create the reminder events.

Am I missing/misunderstanding something here? I figure that whatever times I set in Calendar for an event start or end times should remain to what I set them to and not "jump" to a different time, regardless of the present season, since presumably, Calendar will take into account the actual system time. I presently have Windows clock syncing to the Canadian National Research Council (NRC) atomic clock, and this synchronization process is functioning correctly. Windows automatically changes the system clock to reflect when we transition between Standard and Daylight Saving Time.

Comment 1

[Stefan Sitter [:ssitter]]

Thanks for the detailed bug report. I think you are basically experiencing the same issue as in bug 170169. Do you agree?

Comment 2

[ssafmea]

(In reply to Stefan Sitter from comment #1)
> Thanks for the detailed bug report. I think you are basically experiencing
> the same issue as in bug 170169. Do you agree?

Yes, I agree the problem is similar, except in my case, the time(s) advance ahead by one hour. Further to your comment, I logged into Bugzilla to read about Bug #170169 since I was not familiar with it. After reading about Bug #170169, I decided to experiment some more by creating a new event. I found the following interesting occurence:

1. I create a new event with start date of today (Sept. 23rd) and start time of 02:00AM.

2. I advance the calendar month ahead to February 28th, 2015. I thought of choosing any month between today and March 8th, 2015 (which is when Canada will next switch back to Daylight Saving Time (but we still first need to switch to Standard Time on November 2, 2014). I wanted to see if there was any relationship between Calendar erroneously changing start and/or end times for the event, and the date/time that the change back to Daylight Saving Time is (next) supposed to happen.

3. When I entered the end time of 02:00 for end date of February 28th, 2015, the end time showed 02:00. So far, so good.

4. I changed the event end date to March 7th, 2015 (i.e. the day before our next change over to Daylight Saving Time).

5. I then set the event end time to 02:00 and it showed 02:00. Interesting, since as I reported in my original bug report above, setting the date to March 8th, 2015 and the end time to 02:00 causes the time to immediately change to 03:00.

6. I tried changing the end time for date of March 7th, 2015, to other times (e.g. 01:59, 02:59, 03:00) and they remain showing as set. Good.

7. I changed the event end date to March 8th, 2015 without changing the end time. (The end time was already set to 02:00). As soon as the end date changed to March 8th, 2015, the end time immediately flipped an hour ahead to 03:00 (or if the end time had been set to 02:59, it flipped ahead to 03:59).

8. I then changed the event end date ahead to March 13th, 2016. This is the second Sunday in March, 2016, on which day the change to Daylight Saving Time is to occur.

9. With event end date set to March 13th, 2016, when I tried to set the end time to 02:00, it immediately flipped ahead one hour to 03:00.

10. I changed the end date back by one day to March 12th, 2016 and set the end time to 02:00. The end time remained set to 02:00.

11. I changed the end date ahead to March 14th, 2016 and set the end time to 02:00. The end time remained set to 02:00.

9. The event start time did not appear to change at any point while performing the above changes to the end date or time.


Based on the above additional experiments with the event end date and time, it seems that for some reason, Calendar is somehow aware of the actual date/day when Daylight Saving Time is supposed to occur, and is changing the end time ahead by one hour, perhaps to try and account for the transition from Standard to Daylight Saving Times.

I didn't experiment any more with creating events for the start of Standard Time, beyond what I reported above in my original bug report. However, my original experiment and observations with setting the start date/time for Standard Time appear to also indicate Calendar is somehow aware of the actual date/day/time that Standard Time truly begins and for some reason, Calendar changes the start time (also ahead by one hour to 03:00) if the user sets it to 02:00.

Hope the above additional observations help.


Dave

Comment 3

[ssafmea]

I don't know how/when other countries or states go about changing between Standard and Daylight Saving Times, but the phenomena I describe above seem to revolve around the actual date and times that Canada and I believe the U.S. change over from one Time to another. Aside from the start or end times flipping ahead by one hour when one tries to set them to 02:00, there wouldn't seem to be a problem if one lives in Canada/U.S. However, if Calendar is actually aware of the dates/times that these two countries make the switch, it seems this has implication for other countries/states that change on different dates/times (if they change at all - one Canadian province (Saskatchewan) remains on Standard Time year-round).

Dave