Recurring events that span DST shifts are displayed wrong in winter-time

[Ronald van Engelen]

Recurring events which span the daylight savings shift in autumn and winter are displayed wrong. This renders the current use of schooltool as a school-wide calendar unusable.

For example, giving the following event:
 * Site-wide timezone: Europe/Amsterdam
 * Start (according to edit ui): october 1, 2008 - 09:00
 * Recurrence: weekly for one year

Regarding the start time of this event:
 * according to the schooltool edit ui it starts at 09:00
 * according to the ICS-file it starts at 07:00 UTC each thursday
 * according to all schooltool views it starts at 08:00 in wintertime and starts at 09:00 in summer time

We of course would like to meet each thursday at 09:00 in our local time, regardless of time of year.

This problems seems to be the same as described in http://<email address hidden>/msg00110.html

[Thom Hastings (tghastings)]

I'm going to try, this will be my first bugfix ever.
Any help or mentorship will be appreciated.

[Thom Hastings (tghastings)]

Doing some quick research, it looks like Zoneinfo (http://www.twinsun.com/tz/tz-link.htm) could be helpful.

[Ignas Mikalajūnas (ignas)]

This is because schooltool is storing event start time as a UTC date. So the preferred timezone is only used for date entry/date display at the moment.

It is fixable, but would take a lot of time, as some parts of the system are assuming a uniform date storage format and would have to be fixed as well.

[Tom Hoffman (tom-hoffman)]

Does this happen with timetables and section meeting times as well? That would be a more serious bug.

[Ronald van Engelen (ronalde)]

I've tested this in a test environment (schooltool 2008.10 on jaunty); it doesn't happen with timetables.

[Gerhard Schneider (gs-ilsb)]

How to reproduce the bug:

European DST change was on Oct. 26th this year

Go to the calendar
Create an event on Oct. 23th 22:00-22:30
Repeat every week
Repeat 2 times

Events created: Oct. 23th 22:00-22:30
                          Oct. 30th 21:00-21:30

[Thom Hastings (tghastings)]

oh sweet jesus people how old is this bug?

On Wed, Dec 3, 2014 at 10:15 AM, Douglas Cerna <email address hidden>
wrote:

> ** Changed in: schooltool
> Milestone: 2.8.2 => None
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/306212
>
> Title:
> Recurring events that span DST shifts are displayed wrong in winter-
> time
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[Ronald van Engelen (ronalde-lacocina)]

Thom Hastings (tghastings) wrote 23 hours ago:

> oh sweet jesus people how old is this bug?

According to my calculations, today we should celebrate its 6th birthday.

That's one year younger than my daugther; I guess it's safe to say she has developed a bit more in her first 6 years ;)

[Tom Hoffman (tom-hoffman)]

To be honest, we're probably going to end up "fixing" all the time zone bugs by not letting you change the timezone from UTC. This crappy time zone implementation almost killed the entire project before it even got rolling.