#986283 claws-mail-vcalendar-plugin: Recurring event time incorrectly shifted due to DST

Package:
claws-mail-vcalendar-plugin
Source:
claws-mail
Description:
vCalendar message handling plugin for Claws Mail
Submitter:
Vilius Panevėžys
Date:
2021-04-02 11:06:07 UTC
Severity:
normal
Tags:
#986283#5
Date:
2021-04-02 11:02:33 UTC
From:
To:
Today I noticed a recurring meeting time was shifted ahead by 1 hour: the actual start time is 11:00, vCalendar plug-in displayed start time - 12:00. This is likely due to the fact daylight saving time came into effect on 03-28 this year.

The invitation includes a "VTIMEZONE" block that seems right, except for the strange year (1601) in "DTSTART". Blocks indented for readability.

	BEGIN:VTIMEZONE
		TZID:FLE Standard Time
		BEGIN:STANDARD
			DTSTART:16010101T040000
			TZOFFSETFROM:+0300
			TZOFFSETTO:+0200
			RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=10
		END:STANDARD
		BEGIN:DAYLIGHT
			DTSTART:16010101T030000
			TZOFFSETFROM:+0200
			TZOFFSETTO:+0300
			RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=3
		END:DAYLIGHT
	END:VTIMEZONE

A quick grep through the source does not return any matches for "DAYLIGHT" in neither the source of the package currently in stable, nor upstream, which suggests the property is not supported, hence the upstream tag.