The previous commit asserted southern zones round-trip through iCal unchanged
but verified it only by reasoning. Close that gap with explicit tests:
- A Sydney VTIMEZONE export block: TZID:Australia/Sydney, DAYLIGHT->+1100
(AEDT) / STANDARD->+1000 (AEST), first-Sunday rules (BYMONTH=10/4 BYDAY=1SU),
and DAYLIGHT DTSTART:19701004T020000 — confirming the -480 rule time folds
the from-offset back to the correct local 02:00 AEST transition.
- A southern-zone DTSTART;TZID export -> import round-trip preserving :dtstart.
+7 ical tests (now 63).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
A tz event now exports DTSTART;TZID=<name>:<local> (EXDATE/RDATE likewise;
UNTIL stays UTC per RFC), and the VCALENDAR emits a VTIMEZONE per distinct zone
with DAYLIGHT/STANDARD sub-components generated from the zone's transition rules
(offsets + FREQ=YEARLY;BYMONTH;BYDAY) — London/Paris blocks match real-world
definitions. Clients recur at fixed wall-clock time, DST-correct (prior caveat
gone). Importer tolerates ;TZID= params. 376/376 green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Bug: tz events store wall-clock LOCAL times but export stamped them with a Z
(UTC) suffix, so a London 18:00 event falsely read as 18:00 UTC. ev-ical-conv
now converts a tz event's DTSTART/UNTIL/EXDATE/RDATE local->UTC before
formatting (London summer 18:00 -> 170000Z; Paris -> 160000Z); non-tz events
unchanged. Caveat: UTC RRULE drifts from wall-clock-stable tz recurrence across
a DST boundary (VTIMEZONE deferred). 366/366 green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
ical.sx parses VEVENT/VCALENDAR text back into events (ev/ical-lines->event,
ev/parse-vcalendar): DTSTART/DURATION/RRULE (ordinal BYDAY, BYMONTHDAY, UNTIL/
COUNT/INTERVAL) + EXDATE/RDATE. Round-trip is occurrence-exact — export->import
expands to the identical occurrence set. Completes bidirectional interop.
360/360 green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
ical.sx serializes events to VEVENT/VCALENDAR text for import by standard
clients: UTC basic-format stamps, DURATION (PT#H#M), full RRULE
(FREQ/INTERVAL/COUNT/UNTIL/BYDAY incl. monthly ordinals 2TU/-1FR/BYMONTHDAY)
plus EXDATE/RDATE. Line-oriented (ev/event->ical-lines / ev/events->ical-lines)
with ev/ical-render joining CRLF for the wire format. 332/332 green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
