MMM-CalendarExt3 BST Timezone issue

shall_

@sdetweil
Ok that makes sense. I have found the generated ics file, however it has a 0 file size and when I open it with text editor it is just an empty file. The file type is listed as “Outlook.File.ics.15”

I am using google calendar urls, not sure if that makes any difference? i have tried 3 different urls that I use with the module.

sdetweil

@shall_ weird. are using the same url in mm config?

you might also try it in a browser on your pc. it should download the ics (downloads folder)

shall_

@sdetweil yes i copied each url straight from my config file.
I tried opening them in the browser, it downloaded as described but is still an empty file.

I found a work around by just downloading the ics right from google calendar, this is an example of one of the events. with the timezone tied in.

RPi timezone is set to GMT +1 Europe/London (BST)

BEGIN:VCALENDAR
PRODID:-//Google Inc//Google Calendar 70.9054//EN
VERSION:2.0
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:Work
X-WR-TIMEZONE:Europe/London
BEGIN:VEVENT
DTSTART;VALUE=DATE:20170626
DTEND;VALUE=DATE:20170701
RRULE:FREQ=WEEKLY;WKST=MO;UNTIL=20190331T235959Z;INTERVAL=2;BYDAY=MO
DTSTAMP:20240403T224236Z
UID:15dcXXXXXXujb@google.com
CREATED:20171216T163405Z
LAST-MODIFIED:20190330T214112Z
SEQUENCE:0
STATUS:CONFIRMED
SUMMARY:Earlies
TRANSP:TRANSPARENT
END:VEVENT

shall_

@sdetweil this is another entry added this week with the issue.

BEGIN:VEVENT
DTSTART;VALUE=DATE:20240402
DTEND;VALUE=DATE:20240403
DTSTAMP:20240403T224236Z
UID:70rjap1gXXXXX6oo68db56o@google.com
CREATED:20240402T105500Z
LAST-MODIFIED:20240402T105500Z
SEQUENCE:0
STATUS:CONFIRMED
SUMMARY:12 hours 
TRANSP:OPAQUE
END:VEVENT

sdetweil

@shall_ ok. weird. anyhow

we dont process anything other than vevents. so the garbage at the top which has the x-wr timezone, we dont see.

so the calendar will be processed in the current system timezone.

if you want to see the debug of processing, add the ,“DEBUG” to the end of the logLevel property in config.js

and then start mm like this

npm start >somefile.txt 2>&1

wait til the cal is up, then ctrl-q quit mm and examine the somefile.txt

sdetweil

@shall_ because there is no timezone specified on the entry, it will be processed in the current system timezone

shall_

@sdetweil

I will have to pick this up again tomorrow. i will run the debug when i get home from work.
is there anything I am looking for in particular?

sdetweil

@shall_ because there is a rrule
the string
dates: …
documents the dates returned from the rrule.between function… yesterday plus 1 year
is the window we create to get recurring events

MMRIZE

@shall_
CX3 doesn’t parse ics file directly, so probably the default calendar app (or any event provider) must have responsibility.

But for an instant solution, you can use preProcessor or event payload to make a hotfix by force.

BEFORE

/* in your CX3 module config */
preProcessor: (event) => {
	if (["SomeCalendarName", "AnotherCalendarName"].includes(event.calendarName)) {
		event.startDate = Number(event.startDate) - 1000 * 60 * 60
		event.endDate = Number(event.endDate) - 1000 * 60 * 60
	}
	return event
}

AFTER

If all your calendar has that issue, you can omit if statement.

preProcessor: (event) => {
	event.startDate = Number(event.startDate) - 1000 * 60 * 60
	event.endDate = Number(event.endDate) - 1000 * 60 * 60
	return event
}

shall_

@MMRIZE Thanks for your reply.
The timed calendar events with a start/finish time show the correct time with no issue.

The issue solely lies with all-day and multi-day events.
All of these events during DST showed correctly, as soon as the timezone changed to BST. They now all rollover into the following day, so my 5 day events are now 6 days, 2 days are now 3, single days 2.