RFC 5545, "Internet Calendaring and Scheduling Core Object Specification (iCalendar)", September 2009

Note: This RFC has been updated by RFC 5546, RFC 6868, RFC 7529, RFC 7953, RFC 7986, RFC 9073, RFC 9074, RFC 9253

Errata ID: 5920
Status: Rejected
Type: Technical
Publication Format(s) : TEXT
Reported By: Lars Henriksen
Date Reported: 2019-11-26
Rejected by: Francesca Palombini
Date Rejected: 2024-01-16

Section 3.8.5.3 says:

Every Friday the 13th, forever:

       DTSTART;TZID=America/New_York:19970902T090000
       EXDATE;TZID=America/New_York:19970902T090000
       RRULE:FREQ=MONTHLY;BYDAY=FR;BYMONTHDAY=13

       ==> (1998 9:00 AM EST) February 13;March 13;November 13
           (1999 9:00 AM EDT) August 13
           (2000 9:00 AM EDT) October 13
           ...

It should say:

Every Friday the 13th, forever:

       DTSTART;TZID=America/New_York:19980213T090000
       RRULE:FREQ=MONTHLY;BYDAY=FR;BYMONTHDAY=13

       ==> (1998 9:00 AM EST) February 13;March 13;November 13
           (1999 9:00 AM EDT) August 13
           (2000 9:00 AM EDT) October 13
           ...

Notes:

The "DTSTART" property is not synchronized with the recurrence rule.

Although it may be removed from the recurrence set by an "EXDATE" property, the description at the start of section 3.8.5.3 leaves no doubt that the "DTSTART" property should still be synchronized with the recurrence rule.
--VERIFIER NOTES--
Rejected since it changes the intent of the example (showing exclusion the first instance). The example should be something like the following (possibly to be reported in a new errata):

DTSTART;TZID=America/New_York:19970613T090000
EXDATE;TZID=America/New_York:19970613T090000

See https://mailarchive.ietf.org/arch/msg/calsify/x82GopunVcEh8y5UGSIsEIC3s6M/

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