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Parsing results in wrong time when VTIMEZONE does only contain DAYLIGHT (and no STANDARD)

See original GitHub issue

(Occurs on Android 8 Java and OpenJDK 11)

If this file is parsed:

BEGIN:VCALENDAR
VERSION:2.0
BEGIN:VTIMEZONE
TZID:Europe/Berlin
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
DTSTART:20180325T030000
TZNAME:CEST
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
UID:only-dst@example.com 
DTSTAMP:20180329T084939Z
DTSTART;TZID=Europe/Berlin:20180403T090000
DTEND;TZID=Europe/Berlin:20180403T101500
SUMMARY:Sample Event
CREATED:20180329T084939Z
LAST-MODIFIED:20180329T084939Z
END:VEVENT
END:VCALENDAR

with this code:

    javaClass.classLoader.getResourceAsStream("dst-only-vtimezone.ics").use {
        val ical = CalendarBuilder().build(it)
        val vTZ = ical.getComponent(VTimeZone.VTIMEZONE) as VTimeZone

        assertEquals("Europe/Berlin", vTZ.timeZoneId.value)
        assertEquals(vTZ.observances.first(), vTZ.getApplicableObservance(Date("20180403")))

        val vEvent = ical.getComponent(VEvent.VEVENT) as VEvent
        val start = vEvent.startDate
        assertEquals(vTZ, start.timeZone.vTimeZone)
        assertEquals(1522738800000L, start.date.time)
    }

the test fails. start.date is always 20180402T230000 (start.date.time = 1522702800000L) instead of 20180403T090000 (start.date.time = 1522738800000L).

When the VTIMEZONE is edited so there’s a STANDARD component, it works (even if it does not apply, I have set it to 2020 here):

BEGIN:VCALENDAR
VERSION:2.0
BEGIN:VTIMEZONE
TZID:Europe/Berlin
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
DTSTART:20180325T030000
TZNAME:CEST
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
DTSTART:20200325T030000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
UID:only-dst@example.com 
DTSTAMP:20180329T084939Z
DTSTART;TZID=Europe/Berlin:20180403T090000
DTEND;TZID=Europe/Berlin:20180403T101500
SUMMARY:Sample Event
CREATED:20180329T084939Z
LAST-MODIFIED:20180329T084939Z
END:VEVENT
END:VCALENDAR

results in dtStart = 20180403T090000 Europe/Berlin (UNIX time 1522702800000), as expected.

Issue Analytics

State:
Created 5 years ago
Comments:8 (7 by maintainers)

Top GitHub Comments

2reactions

benfortunacommented, Jul 8, 2019

Just released ical4j 2.2.5 with a potential fix for this. Appreciate any feedback/confirmation of this fix. Many thanks.

1reaction

benfortunacommented, Aug 7, 2019

Apologies I thought I had also released in 3.x branch. Will make a release including the fix shortly.

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