RFC Errata
Found 22 records.
Status: Verified (21)
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
Source of RFC: calsify (app)
Errata ID: 1911
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Bernard Desruisseaux
Date Reported: 2009-10-13
Verifier Name: Alexey Melnikov
Date Verified: 2009-10-13
Section 2.1 says:
| DQUOTE | 22 |
It should say:
| DQUOTE | 34 |
Notes:
The codepoint for the DQUOTE character was erroneously specified in hexadecimal instead of decimal. Issue was found by Raimund Nisius.
Errata ID: 1913
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Anshul Agrawal
Date Reported: 2009-10-13
Verifier Name: Alexey Melnikov
Date Verified: 2010-07-07
Section 3.3.10 says:
represents the last Monday of the month. The numeric value in a BYDAY rule part with the FREQ rule part set to YEARLY corresponds to an offset within the month when the BYMONTH rule part is present, and corresponds to an offset within the year when the BYWEEKNO or BYMONTH rule parts are present. If an integer
It should say:
represents the last Monday of the month. The numeric value in a
BYDAY rule part with the FREQ rule part set to YEARLY corresponds
to an offset within the month when the BYMONTH rule part is
present, and corresponds to an offset within the year when the
BYWEEKNO or BYMONTH rule parts are not present. If an integer
^^^
Notes:
The original statement appears contradictory in itself.
Errata ID: 1916
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Alexey Melnikov
Date Reported: 2009-10-15
Verifier Name: Lisa Dusseault
Date Verified: 2010-03-10
Section 3.6.4 says:
BEGIN:VFREEBUSY
UID:19970901T115957Z-76A912@example.com
DTSTAMP:19970901T120000Z
ORGANIZER:jsmith@example.com
^
It should say:
BEGIN:VFREEBUSY
UID:19970901T115957Z-76A912@example.com
DTSTAMP:19970901T120000Z
ORGANIZER:mailto:jsmith@example.com
^^^^^^^
Notes:
The last example in section 3.6.4 is missing "mailto:" after the "ORGANIZER:"
Errata ID: 2039
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Arnout Engelen
Date Reported: 2010-02-10
Verifier Name: Alexey Melnikov
Date Verified: 2010-02-15
Section 4 says:
BEGIN:VALARM
ACTION:AUDIO
TRIGGER:19980403T120000Z
ATTACH;FMTTYPE=audio/basic:http://example.com/pub/audio-
files/ssbanner.aud
REPEAT:4
DURATION:PT1H
END:VALARM
It should say:
BEGIN:VALARM
ACTION:AUDIO
TRIGGER;VALUE=DATE-TIME:19980403T120000Z
ATTACH;FMTTYPE=audio/basic:http://example.com/pub/audio-
files/ssbanner.aud
REPEAT:4
DURATION:PT1H
END:VALARM
Notes:
The trigger is presented as a DATE-TIME, but the default type of this field is DURATION (3.8.6.3). Either the type must be specified (as per the corrected text), or specified in DURATION format.
Errata ID: 4271
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Neil Jenkins
Date Reported: 2015-02-12
Verifier Name: Barry Leiba
Date Verified: 2015-02-17
Section 3.3.10 says:
Recurrence rules may generate recurrence instances with an invalid date (e.g., February 30) or nonexistent local time (e.g., 1:30 AM on a day where the local time is moved forward by an hour at 1:00 AM). Such recurrence instances MUST be ignored and MUST NOT be counted as part of the recurrence set.
It should say:
Recurrence rules may generate recurrence instances with an invalid date (e.g., February 30). Such recurrence instances MUST be ignored and MUST NOT be counted as part of the recurrence set. Recurrence rules may generate recurrence instances with a nonexistent local time ((e.g., 1:30 AM on a day where the local time is moved forward by an hour at 1:00 AM). Such recurrence instances are handled as specified in Section 3.3.5.
Notes:
The section about ignoring times that don't occur in the timezone of the expansion is contradicted by the later passage (p44):
"""If the computed local start time of a recurrence instance does not
exist, or occurs more than once, for the specified time zone, the
time of the recurrence instance is interpreted in the same manner
as an explicit DATE-TIME value describing that date and time, as
specified in Section 3.3.5."""
And this is the behaviour implemented by major clients such as Calendar.app and Google Calendar.
Errata ID: 2677
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Bernard Desruisseaux
Date Reported: 2010-12-21
Verifier Name: Alexey Melnikov
Date Verified: 2011-01-20
Section 3.8.1.10 says:
Conformance:
This property can be specified once in "VEVENT" or "VTODO" calendar component.
^^^^
It should say:
Conformance: This property can be specified in "VEVENT" or "VTODO" calendar component.
Notes:
The word "once" was mistakenly introduced in RFC 5545.
RFC 2445 didn't have this issue.
Issues was previously reported by Dennis Gearon <gearond@sbcglobal.net>
(See Errata 2676) but proposed the wrong correction.
Errata ID: 3740
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Daniel Barkalow
Date Reported: 2013-09-29
Verifier Name: Barry Leiba
Date Verified: 2013-10-08
Section 4 says:
BEGIN:VTIMEZONE
TZID:America/New_York
BEGIN:STANDARD
DTSTART:19981025T020000
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:EST
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:19990404T020000
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
END:DAYLIGHT
END:VTIMEZONE
It should say:
BEGIN:VTIMEZONE TZID:America/New_York BEGIN:STANDARD DTSTART:19671029T020000 RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU;UNTIL=20061029T060000Z TZOFFSETFROM:-0400 TZOFFSETTO:-0500 TZNAME:EST END:STANDARD BEGIN:DAYLIGHT DTSTART:19870405T020000 RRULE:FREQ=YEARLY;BYMONTH=4;BYDAY=1SU;UNTIL=20060402T070000Z TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT END:DAYLIGHT END:VTIMEZONE
Notes:
The time zone specification in the original example does not cover the event in the example (which occurs on 19980312, before both of the listed onsets).
---- Verifier notes -----
The corrected text uses part of the VTIMEZONE definition in the example on page 68.
Errata ID: 3779
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Daniele Mancini
Date Reported: 2013-10-31
Verifier Name: Barry Leiba
Date Verified: 2013-10-31
Section 3.3.10 says:
represents the last Monday of the month. The numeric value in a BYDAY rule part with the FREQ rule part set to YEARLY corresponds to an offset within the month when the BYMONTH rule part is present, and corresponds to an offset within the year when the BYWEEKNO or BYMONTH rule parts are present. If an integer modifier is not present, it means all days of this type within the specified frequency. For example, within a MONTHLY rule, MO represents all Mondays within the month. The BYDAY rule part MUST NOT be specified with a numeric value when the FREQ rule part is not set to MONTHLY or YEARLY. Furthermore, the BYDAY rule part MUST NOT be specified with a numeric value with the FREQ rule part set to YEARLY when the BYWEEKNO rule part is specified.
It should say:
represents the last Monday of the month. The numeric value in a BYDAY rule part with the FREQ rule part set to YEARLY corresponds to an offset within the month when the BYMONTH rule part is present, and corresponds to an offset within the year when the BYMONTH rule part is not present. If an integer modifier is not present, it means all days of this type within the specified frequency. For example, within a MONTHLY rule, MO represents all Mondays within the month. The BYDAY rule part MUST NOT be specified with a numeric value when the FREQ rule part is not set to MONTHLY or YEARLY. Furthermore, the BYDAY rule part MUST NOT be specified with a numeric value with the FREQ rule part set to YEARLY when the BYWEEKNO rule part is specified.
Notes:
Other than the missing 'not', pointed out in the errata 1913, the original text contradicts itself regarding BYWEEKNO.
At the beggining of the paragraph, it says that when using a YEARLY frequency with BYWEEKNO rule part, the integer part identifies an offset within the year (i.e. either in [-53, 0) or (0, 53], as it can be a week day in a valid week of the year, even if it is not clearly specified), but at the end of the paragraph, it states that offsets should not be specified in conjunction with a BYWEEKNO rule part.
Errata ID: 3883
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Bruce Florman
Date Reported: 2014-02-05
Verifier Name: Barry Leiba
Date Verified: 2014-02-14
Section 3.8.5.3 says:
Every 3 hours from 9:00 AM to 5:00 PM on a specific day:
DTSTART;TZID=America/New_York:19970902T090000
RRULE:FREQ=HOURLY;INTERVAL=3;UNTIL=19970902T170000Z
==> (September 2, 1997 EDT) 09:00,12:00,15:00
It should say:
Every 3 hours from 9:00 AM to 5:00 PM on a specific day:
DTSTART;TZID=America/New_York:19970902T090000
RRULE:FREQ=HOURLY;INTERVAL=3;UNTIL=19970902T210000Z
==> (September 2, 1997 EDT) 09:00,12:00,15:00
Notes:
The UNTIL rule part is specified with UTC time, which was four hours ahead of America/New_York on 19970902. So 170000Z would only be 1:00 PM on that day.
The corrected UNTIL rule matches the description (from 9 to 5). Note that "UNTIL=19970902T190000Z" would have the same effect (the last event is at 3 PM in New York, which is 19:00 Z), but 21:00 Z is what matches the description.
Errata ID: 4149
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Hiroaki KAWAI
Date Reported: 2014-10-29
Verifier Name: Barry Leiba
Date Verified: 2014-10-30
Section 4 says:
BEGIN:VCALENDAR VERSION:2.0 PRODID:-//RDU Software//NONSGML HandCal//EN BEGIN:VFREEBUSY ORGANIZER:mailto:jsmith@example.com DTSTART:19980313T141711Z DTEND:19980410T141711Z
It should say:
BEGIN:VCALENDAR VERSION:2.0 PRODID:-//RDU Software//NONSGML HandCal//EN BEGIN:VFREEBUSY UID:19970901T115957Z-76A912@example.com DTSTAMP:19970901T120000Z ORGANIZER:mailto:jsmith@example.com DTSTART:19980313T141711Z DTEND:19980410T141711Z
Notes:
3.6.4 says
fbprop = *(
;
; The following are REQUIRED,
; but MUST NOT occur more than once.
;
dtstamp / uid /
Errata ID: 6109
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Lars Henriksen
Date Reported: 2020-04-19
Verifier Name: Francesca Palombini
Date Verified: 2024-01-16
Section 3.6.1 says:
The anniversary type of "VEVENT" can span more than one date (i.e., "DTEND" property value is set to a calendar date after the "DTSTART" property value).
It should say:
The anniversary type of "VEVENT" can span more than one date (i.e., "DTEND" property value is set to a calendar date at least two days after the "DTSTART" property value).
Notes:
"DTEND" comes, by definition (3.8.2.2), always after "DTSTART". The span (duration) is the difference between the two.
Errata ID: 7691
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Tom Sydney Kerckhove
Date Reported: 2023-10-30
Verifier Name: Murray Kucherawy
Date Verified: 2023-11-01
Section 3.8.4.2 says:
The following is an example of this property with an alternate representation of an LDAP URI to a directory entry containing the contact information: CONTACT;ALTREP="ldap://example.com:6666/o=ABC%20Industries\, c=US???(cn=Jim%20Dolittle)":Jim Dolittle\, ABC Industries\, +1-919-555-1234
It should say:
The following is an example of this property with an alternate representation of an LDAP URI to a directory entry containing the contact information: CONTACT;ALTREP="ldap://example.com:6666/o=ABC%20Industries, c=US???(cn=Jim%20Dolittle)":Jim Dolittle\, ABC Industries\, +1-919-555-1234
Notes:
Note that the original text has an escaped comma in the ALTREP parameter value at the end of the unfolded line.
The characters '\' and ',' are allowed in quoted parameter values.
This means that the URL must be parsed as
"ldap://example.com:6666/o=ABC%20Industries\,c=US???(cn=Jim%20Dolittle)"
but this is not a valid URI because of the extra backslash.
Because commas do not need to be escaped in quoted parameter values, I assume that this is an error and the comma should not have been quoted.
Errata ID: 2497
Status: Verified
Type: Editorial
Publication Format(s) : TEXT
Reported By: Scott Furry
Date Reported: 2010-08-21
Verifier Name: Peter Saint-Andre
Date Verified: 2010-09-14
Section 2.1 (pg 7) says:
+------------------------+-------------------+
| Character name | Decimal codepoint |
+------------------------+-------------------+
| HTAB | 9 |
| LF | 10 |
| CR | 13 |
--> | DQUOTE | 22 |
--> | SPACE | 32 |
... table continues
It should say:
+------------------------+-------------------+
| Character name | Decimal codepoint |
+------------------------+-------------------+
| HTAB | 9 |
| LF | 10 |
| CR | 13 |
--> | SPACE | 32 |
--> | DQUOTE | 34 |
^^
corrected value
...table continues
Notes:
Correction to Table on page 7 of RFC updating the order of ASCII-US listing (decimal codepoint descending) and incorporating errata ID 1911(2009-10-13 - DQUOTE char listing shows hexadecimal value).
Errata ID: 2038
Status: Verified
Type: Editorial
Publication Format(s) : TEXT
Reported By: Arnout Engelen
Date Reported: 2010-02-10
Verifier Name: Alexey Melnikov
Date Verified: 2010-02-15
Section Appendix A says:
5. The "DURATION" property can no longer appear in "VFREEBUSY"
components.
A.2. Restrictions Removed
It should say:
5. The "DURATION" property can no longer appear in "VFREEBUSY"
components.
6. Use of the "charset" Content-Type parameter in MIME transports
is now mandatory.
A.2. Restrictions Removed
Notes:
One change is missing from the list of changes.
Errata ID: 2516
Status: Verified
Type: Editorial
Publication Format(s) : TEXT
Reported By: David Wright
Date Reported: 2010-09-13
Verifier Name: Peter Saint-Andre
Date Verified: 2010-09-14
Section 3.8.4.1 says:
Example: The following is an example of this property's use when
another calendar user is acting on behalf of the "Attendee":
ATTENDEE;SENT-BY=mailto:jan_doe@example.com;CN=John Smith:
mailto:jsmith@example.com
It should say:
Example: The following is an example of this property's use when
another calendar user is acting on behalf of the "Attendee":
ATTENDEE;SENT-BY="mailto:jan_doe@example.com";CN=John Smith:
^ ^
mailto:jsmith@example.com
Notes:
In the specification for SENT-BY (3.2.18), the r-value MUST be explicitly bound by DQUOTEs (ABNF follows)
sentbyparam = "SENT-BY" "=" DQUOTE cal-address DQUOTE
Errata ID: 2527
Status: Verified
Type: Editorial
Publication Format(s) : TEXT
Reported By: David Wright
Date Reported: 2010-09-20
Verifier Name: Alexey Melnikov
Date Verified: 2010-11-04
Section 3.8.5.2 says:
Example: The following are examples of this property:
RDATE:19970714T123000Z
RDATE;TZID=America/New_York:19970714T083000
RDATE;VALUE=PERIOD:19960403T020000Z/19960403T040000Z,
19960404T010000Z/PT3H
RDATE;VALUE=DATE:19970101,19970120,19970217,19970421
19970526,19970704,19970901,19971014,19971128,19971129,19971225
It should say:
Example: The following are examples of this property:
RDATE:19970714T123000Z
RDATE;TZID=America/New_York:19970714T083000
RDATE;VALUE=PERIOD:19960403T020000Z/19960403T040000Z,
19960404T010000Z/PT3H
RDATE;VALUE=DATE:19970101,19970120,19970217,19970421,
^
19970526,19970704,19970901,19971014,19971128,19971129,19971225
Notes:
Comma missing at the fold boundary.
Errata ID: 3747
Status: Verified
Type: Editorial
Publication Format(s) : TEXT
Reported By: Alfie John
Date Reported: 2013-10-09
Verifier Name: Barry Leiba
Date Verified: 2013-10-26
Section 3.3.10 says:
+----------+--------+--------+-------+-------+------+-------+------+
| |SECONDLY|MINUTELY|HOURLY |DAILY |WEEKLY|MONTHLY|YEARLY|
+----------+--------+--------+-------+-------+------+-------+------+
|BYMONTH |Limit |Limit |Limit |Limit |Limit |Limit |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYWEEKNO |N/A |N/A |N/A |N/A |N/A |N/A |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYYEARDAY |Limit |Limit |Limit |N/A |N/A |N/A |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYMONTHDAY|Limit |Limit |Limit |Limit |N/A |Expand |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYDAY |Limit |Limit |Limit |Limit |Expand|Note 1 |Note 2|
+----------+--------+--------+-------+-------+------+-------+------+
|BYHOUR |Limit |Limit |Limit |Expand |Expand|Expand |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYMINUTE |Limit |Limit |Expand |Expand |Expand|Expand |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYSECOND |Limit |Expand |Expand |Expand |Expand|Expand |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYSETPOS |Limit |Limit |Limit |Limit |Limit |Limit |Limit |
+----------+--------+--------+-------+-------+------+-------+------+
Note 1: Limit if BYMONTHDAY is present; otherwise, special expand
for MONTHLY.
Note 2: Limit if BYYEARDAY or BYMONTHDAY is present; otherwise,
special expand for WEEKLY if BYWEEKNO present; otherwise,
special expand for MONTHLY if BYMONTH present; otherwise,
special expand for YEARLY.
It should say:
+----------+--------+--------+-------+-------+------+-------+------+
| |SECONDLY|MINUTELY|HOURLY |DAILY |WEEKLY|MONTHLY|YEARLY|
+----------+--------+--------+-------+-------+------+-------+------+
|BYMONTH |Limit |Limit |Limit |Limit |Limit |Limit |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYWEEKNO |N/A |N/A |N/A |N/A |N/A |N/A |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYYEARDAY |Limit |Limit |Limit |N/A |N/A |N/A |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYMONTHDAY|Limit |Limit |Limit |Limit |N/A |Expand |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYDAY |Limit |Limit |Limit |Limit |Expand|Note 1 |Note 2|
+----------+--------+--------+-------+-------+------+-------+------+
|BYHOUR |Limit |Limit |Limit |Expand |Expand|Expand |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYMINUTE |Limit |Limit |Expand |Expand |Expand|Expand |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYSECOND |Limit |Expand |Expand |Expand |Expand|Expand |Expand|
+----------+--------+--------+-------+-------+------+-------+------+
|BYSETPOS |Limit |Limit |Limit |Limit |Limit |Limit |Limit |
+----------+--------+--------+-------+-------+------+-------+------+
Note 1: Limit if BYMONTHDAY is present; otherwise, special expand
for MONTHLY.
Note 2: Limit if BYYEARDAY or BYMONTHDAY is present; otherwise,
special expand for YEARLY.
Notes:
The change is to "Note 2":
Removed WEEKLY and MONTHLY clause as Note 2 only applies to FREQ = YEARLY.
Errata ID: 4414
Status: Verified
Type: Editorial
Publication Format(s) : TEXT
Reported By: Joseph Silvestre
Date Reported: 2015-07-10
Verifier Name: Barry Leiba
Date Verified: 2015-07-21
Section 3.3.10 says:
The UNTIL rule part defines a DATE or DATE-TIME value that bounds
the recurrence rule in an inclusive manner. If the value
specified by UNTIL is synchronized with the specified recurrence,
this DATE or DATE-TIME becomes the last instance of the
recurrence. The value of the UNTIL rule part MUST have the same
value type as the "DTSTART" property. Furthermore, if the
"DTSTART" property is specified as a date with local time, then
the UNTIL rule part MUST also be specified as a date with local
time. If the "DTSTART" property is specified as a date with UTC
time or a date with local time and time zone reference, then the
UNTIL rule part MUST be specified as a date with UTC time. In the
case of the "STANDARD" and "DAYLIGHT" sub-components the UNTIL
rule part MUST always be specified as a date with UTC time. If
specified as a DATE-TIME value, then it MUST be specified in a UTC
time format. If not present, and the COUNT rule part is also not
present, the "RRULE" is considered to repeat forever.
It should say:
The UNTIL rule part defines a DATE or DATE-TIME value that bounds
the recurrence rule in an inclusive manner. If the value
specified by UNTIL is synchronized with the specified recurrence,
this DATE or DATE-TIME becomes the last instance of the
recurrence. The value of the UNTIL rule part MUST have the same
value type as the "DTSTART" property. Furthermore, if the
"DTSTART" property is specified as a date with local time, then
the UNTIL rule part MUST also be specified as a date with local
time. If the "DTSTART" property is specified as a date with UTC
time or a date with local time and time zone reference, then the
UNTIL rule part MUST be specified as a date with UTC time. In the
case of the "STANDARD" and "DAYLIGHT" sub-components the UNTIL
rule part MUST always be specified as a date with UTC time.
If not present, and the COUNT rule part is also not
present, the "RRULE" is considered to repeat forever.
Notes:
The following sentence from RFC 2445 should have been removed from the text.
If
specified as a DATE-TIME value, then it MUST be specified in a UTC
time format.
Errata ID: 5602
Status: Verified
Type: Editorial
Publication Format(s) : TEXT
Reported By: Carsten Bormann
Date Reported: 2019-01-15
Verifier Name: Francesca Palombini
Date Verified: 2024-01-16
Section 3.1.3 says:
ATTACH;FMTTYPE=text/plain;ENCODING=BASE64;VALUE=BINARY:VGhlIH
F1aWNrIGJyb3duIGZveCBqdW1wcyBvdmVyIHRoZSBsYXp5IGRvZy4
It should say:
ATTACH;FMTTYPE=text/plain;ENCODING=BASE64;VALUE=BINARY:VGhlIH
F1aWNrIGJyb3duIGZveCBqdW1wcyBvdmVyIHRoZSBsYXp5IGRvZy4=
Notes:
The base64 text used in the example misses the base64 padding. RFC 5545 appears to be using base64 according to RFC 4648 Section 4 with padding throughout, except for this example. (The corrected text decodes to "The quick brown fox jumps over the lazy dog.") Beyond temporary confusion in implementers, it is possible that this example will turn up in a test suite and ultimately cause unnecessarily lenient behavior of decoders ("soup"); it should be either clarified that this lenient behavior is not the intention or the behavior should be codified.
Errata ID: 5794
Status: Verified
Type: Editorial
Publication Format(s) : TEXT
Reported By: Eugene Adell
Date Reported: 2019-07-28
Verifier Name: Barry Leiba
Date Verified: 2020-12-15
Section ToC says:
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Basic Grammar and Conventions . . . . . . . . . . . . . . . . 6
2.1. Formatting Conventions . . . . . . . . . . . . . . . . . 6
2.2. Related Memos . . . . . . . . . . . . . . . . . . . . . . 7
3. iCalendar Object Specification . . . . . . . . . . . . . . . 8
3.1. Content Lines . . . . . . . . . . . . . . . . . . . . . . 8
3.1.1. List and Field Separators . . . . . . . . . . . . . . 11
3.1.2. Multiple Values . . . . . . . . . . . . . . . . . . . 11
3.1.3. Binary Content . . . . . . . . . . . . . . . . . . . 11
3.1.4. Character Set . . . . . . . . . . . . . . . . . . . . 12
3.2. Property Parameters . . . . . . . . . . . . . . . . . . . 12
3.2.1. Alternate Text Representation . . . . . . . . . . . . 13
3.2.2. Common Name . . . . . . . . . . . . . . . . . . . . . 15
3.2.3. Calendar User Type . . . . . . . . . . . . . . . . . 15
3.2.4. Delegators . . . . . . . . . . . . . . . . . . . . . 16
3.2.5. Delegatees . . . . . . . . . . . . . . . . . . . . . 16
3.2.6. Directory Entry Reference . . . . . . . . . . . . . . 17
3.2.7. Inline Encoding . . . . . . . . . . . . . . . . . . . 17
3.2.8. Format Type . . . . . . . . . . . . . . . . . . . . . 18
3.2.9. Free/Busy Time Type . . . . . . . . . . . . . . . . . 19
3.2.10. Language . . . . . . . . . . . . . . . . . . . . . . 20
3.2.11. Group or List Membership . . . . . . . . . . . . . . 20
3.2.12. Participation Status . . . . . . . . . . . . . . . . 21
3.2.13. Recurrence Identifier Range . . . . . . . . . . . . . 22
3.2.14. Alarm Trigger Relationship . . . . . . . . . . . . . 23
3.2.15. Relationship Type . . . . . . . . . . . . . . . . . . 24
3.2.16. Participation Role . . . . . . . . . . . . . . . . . 25
3.2.17. RSVP Expectation . . . . . . . . . . . . . . . . . . 25
3.2.18. Sent By . . . . . . . . . . . . . . . . . . . . . . . 26
3.2.19. Time Zone Identifier . . . . . . . . . . . . . . . . 26
3.2.20. Value Data Types . . . . . . . . . . . . . . . . . . 28
3.3. Property Value Data Types . . . . . . . . . . . . . . . . 29
3.3.1. Binary . . . . . . . . . . . . . . . . . . . . . . . 29
3.3.2. Boolean . . . . . . . . . . . . . . . . . . . . . . . 30
3.3.3. Calendar User Address . . . . . . . . . . . . . . . . 30
3.3.4. Date . . . . . . . . . . . . . . . . . . . . . . . . 31
3.3.5. Date-Time . . . . . . . . . . . . . . . . . . . . . . 31
3.3.6. Duration . . . . . . . . . . . . . . . . . . . . . . 34
3.3.7. Float . . . . . . . . . . . . . . . . . . . . . . . . 35
3.3.8. Integer . . . . . . . . . . . . . . . . . . . . . . . 35
3.3.9. Period of Time . . . . . . . . . . . . . . . . . . . 36
3.3.10. Recurrence Rule . . . . . . . . . . . . . . . . . . . 37
3.3.11. Text . . . . . . . . . . . . . . . . . . . . . . . . 45
3.3.12. Time . . . . . . . . . . . . . . . . . . . . . . . . 46
3.3.13. URI . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.3.14. UTC Offset . . . . . . . . . . . . . . . . . . . . . 49
3.4. iCalendar Object . . . . . . . . . . . . . . . . . . . . 49
3.5. Property . . . . . . . . . . . . . . . . . . . . . . . . 50
3.6. Calendar Components . . . . . . . . . . . . . . . . . . . 50
3.6.1. Event Component . . . . . . . . . . . . . . . . . . . 52
3.6.2. To-Do Component . . . . . . . . . . . . . . . . . . . 56
3.6.3. Journal Component . . . . . . . . . . . . . . . . . . 58
3.6.4. Free/Busy Component . . . . . . . . . . . . . . . . . 60
3.6.5. Time Zone Component . . . . . . . . . . . . . . . . . 63
3.6.6. Alarm Component . . . . . . . . . . . . . . . . . . . 72
3.7. Calendar Properties . . . . . . . . . . . . . . . . . . . 77
3.7.1. Calendar Scale . . . . . . . . . . . . . . . . . . . 77
3.7.2. Method . . . . . . . . . . . . . . . . . . . . . . . 78
3.7.3. Product Identifier . . . . . . . . . . . . . . . . . 79
3.7.4. Version . . . . . . . . . . . . . . . . . . . . . . . 80
3.8. Component Properties . . . . . . . . . . . . . . . . . . 81
3.8.1. Descriptive Component Properties . . . . . . . . . . 81
3.8.1.1. Attachment . . . . . . . . . . . . . . . . . . . 81
3.8.1.2. Categories . . . . . . . . . . . . . . . . . . . 82
3.8.1.3. Classification . . . . . . . . . . . . . . . . . 83
3.8.1.4. Comment . . . . . . . . . . . . . . . . . . . . . 84
3.8.1.5. Description . . . . . . . . . . . . . . . . . . . 85
3.8.1.6. Geographic Position . . . . . . . . . . . . . . . 87
3.8.1.7. Location . . . . . . . . . . . . . . . . . . . . 88
3.8.1.8. Percent Complete . . . . . . . . . . . . . . . . 89
3.8.1.9. Priority . . . . . . . . . . . . . . . . . . . . 90
3.8.1.10. Resources . . . . . . . . . . . . . . . . . . . . 92
3.8.1.11. Status . . . . . . . . . . . . . . . . . . . . . 93
3.8.1.12. Summary . . . . . . . . . . . . . . . . . . . . . 94
3.8.2. Date and Time Component Properties . . . . . . . . . 95
3.8.2.1. Date-Time Completed . . . . . . . . . . . . . . . 95
3.8.2.2. Date-Time End . . . . . . . . . . . . . . . . . . 96
3.8.2.3. Date-Time Due . . . . . . . . . . . . . . . . . . 97
3.8.2.4. Date-Time Start . . . . . . . . . . . . . . . . . 99
3.8.2.5. Duration . . . . . . . . . . . . . . . . . . . . 100
3.8.2.6. Free/Busy Time . . . . . . . . . . . . . . . . . 101
3.8.2.7. Time Transparency . . . . . . . . . . . . . . . . 102
3.8.3. Time Zone Component Properties . . . . . . . . . . . 103
3.8.3.1. Time Zone Identifier . . . . . . . . . . . . . . 103
3.8.3.2. Time Zone Name . . . . . . . . . . . . . . . . . 105
3.8.3.3. Time Zone Offset From . . . . . . . . . . . . . . 106
3.8.3.4. Time Zone Offset To . . . . . . . . . . . . . . . 106
3.8.3.5. Time Zone URL . . . . . . . . . . . . . . . . . . 107
3.8.4. Relationship Component Properties . . . . . . . . . . 108
3.8.4.1. Attendee . . . . . . . . . . . . . . . . . . . . 108
3.8.4.2. Contact . . . . . . . . . . . . . . . . . . . . . 111
3.8.4.3. Organizer . . . . . . . . . . . . . . . . . . . . 113
3.8.4.4. Recurrence ID . . . . . . . . . . . . . . . . . . 114
3.8.4.5. Related To . . . . . . . . . . . . . . . . . . . 117
3.8.4.6. Uniform Resource Locator . . . . . . . . . . . . 118
3.8.4.7. Unique Identifier . . . . . . . . . . . . . . . . 119
3.8.5. Recurrence Component Properties . . . . . . . . . . . 120
3.8.5.1. Exception Date-Times . . . . . . . . . . . . . . 120
3.8.5.2. Recurrence Date-Times . . . . . . . . . . . . . . 122
3.8.5.3. Recurrence Rule . . . . . . . . . . . . . . . . . 124
3.8.6. Alarm Component Properties . . . . . . . . . . . . . 134
3.8.6.1. Action . . . . . . . . . . . . . . . . . . . . . 134
3.8.6.2. Repeat Count . . . . . . . . . . . . . . . . . . 135
3.8.6.3. Trigger . . . . . . . . . . . . . . . . . . . . . 135
3.8.7. Change Management Component Properties . . . . . . . 138
3.8.7.1. Date-Time Created . . . . . . . . . . . . . . . . 138
3.8.7.2. Date-Time Stamp . . . . . . . . . . . . . . . . . 139
3.8.7.3. Last Modified . . . . . . . . . . . . . . . . . . 140
3.8.7.4. Sequence Number . . . . . . . . . . . . . . . . . 141
3.8.8. Miscellaneous Component Properties . . . . . . . . . 142
3.8.8.1. IANA Properties . . . . . . . . . . . . . . . . . 142
3.8.8.2. Non-Standard Properties . . . . . . . . . . . . . 142
3.8.8.3. Request Status . . . . . . . . . . . . . . . . . 144
4. iCalendar Object Examples . . . . . . . . . . . . . . . . . . 146
5. Recommended Practices . . . . . . . . . . . . . . . . . . . . 150
6. Internationalization Considerations . . . . . . . . . . . . . 151
7. Security Considerations . . . . . . . . . . . . . . . . . . . 151
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 151
8.1. iCalendar Media Type Registration . . . . . . . . . . . . 151
8.2. New iCalendar Elements Registration . . . . . . . . . . . 155
8.2.1. iCalendar Elements Registration Procedure . . . . . . 155
8.2.2. Registration Template for Components . . . . . . . . 155
8.2.3. Registration Template for Properties . . . . . . . . 156
8.2.4. Registration Template for Parameters . . . . . . . . 156
8.2.5. Registration Template for Value Data Types . . . . . 157
8.2.6. Registration Template for Values . . . . . . . . . . 157
8.3. Initial iCalendar Elements Registries . . . . . . . . . . 158
8.3.1. Components Registry . . . . . . . . . . . . . . . . . 158
8.3.2. Properties Registry . . . . . . . . . . . . . . . . . 158
8.3.3. Parameters Registry . . . . . . . . . . . . . . . . . 161
8.3.4. Value Data Types Registry . . . . . . . . . . . . . . 162
8.3.5. Calendar User Types Registry . . . . . . . . . . . . 162
8.3.6. Free/Busy Time Types Registry . . . . . . . . . . . . 163
8.3.7. Participation Statuses Registry . . . . . . . . . . . 163
8.3.8. Relationship Types Registry . . . . . . . . . . . . . 164
8.3.9. Participation Roles Registry . . . . . . . . . . . . 164
8.3.10. Actions Registry . . . . . . . . . . . . . . . . . . 165
8.3.11. Classifications Registry . . . . . . . . . . . . . . 165
8.3.12. Methods Registry . . . . . . . . . . . . . . . . . . 165
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 165
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 166
10.1. Normative References . . . . . . . . . . . . . . . . . . 166
10.2. Informative References . . . . . . . . . . . . . . . . . 167
Appendix A. Differences from RFC 2445 . . . . . . . . . . . . . 169
A.1. New Restrictions . . . . . . . . . . . . . . . . . . . . 169
A.2. Restrictions Removed . . . . . . . . . . . . . . . . . . 169
A.3. Deprecated Features . . . . . . . . . . . . . . . . . . . 169
It should say:
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Basic Grammar and Conventions . . . . . . . . . . . . . . . . 6
2.1. Formatting Conventions . . . . . . . . . . . . . . . . . 6
2.2. Related Memos . . . . . . . . . . . . . . . . . . . . . . 8
3. iCalendar Object Specification . . . . . . . . . . . . . . . 8
3.1. Content Lines . . . . . . . . . . . . . . . . . . . . . . 9
3.1.1. List and Field Separators . . . . . . . . . . . . . . 11
3.1.2. Multiple Values . . . . . . . . . . . . . . . . . . . 12
3.1.3. Binary Content . . . . . . . . . . . . . . . . . . . 12
3.1.4. Character Set . . . . . . . . . . . . . . . . . . . . 13
3.2. Property Parameters . . . . . . . . . . . . . . . . . . . 13
3.2.1. Alternate Text Representation . . . . . . . . . . . . 14
3.2.2. Common Name . . . . . . . . . . . . . . . . . . . . . 15
3.2.3. Calendar User Type . . . . . . . . . . . . . . . . . 16
3.2.4. Delegators . . . . . . . . . . . . . . . . . . . . . 17
3.2.5. Delegatees . . . . . . . . . . . . . . . . . . . . . 17
3.2.6. Directory Entry Reference . . . . . . . . . . . . . . 18
3.2.7. Inline Encoding . . . . . . . . . . . . . . . . . . . 18
3.2.8. Format Type . . . . . . . . . . . . . . . . . . . . . 19
3.2.9. Free/Busy Time Type . . . . . . . . . . . . . . . . . 20
3.2.10. Language . . . . . . . . . . . . . . . . . . . . . . 21
3.2.11. Group or List Membership . . . . . . . . . . . . . . 21
3.2.12. Participation Status . . . . . . . . . . . . . . . . 22
3.2.13. Recurrence Identifier Range . . . . . . . . . . . . . 23
3.2.14. Alarm Trigger Relationship . . . . . . . . . . . . . 24
3.2.15. Relationship Type . . . . . . . . . . . . . . . . . . 25
3.2.16. Participation Role . . . . . . . . . . . . . . . . . 25
3.2.17. RSVP Expectation . . . . . . . . . . . . . . . . . . 26
3.2.18. Sent By . . . . . . . . . . . . . . . . . . . . . . . 27
3.2.19. Time Zone Identifier . . . . . . . . . . . . . . . . 27
3.2.20. Value Data Types . . . . . . . . . . . . . . . . . . 29
3.3. Property Value Data Types . . . . . . . . . . . . . . . . 30
3.3.1. Binary . . . . . . . . . . . . . . . . . . . . . . . 30
3.3.2. Boolean . . . . . . . . . . . . . . . . . . . . . . . 31
3.3.3. Calendar User Address . . . . . . . . . . . . . . . . 31
3.3.4. Date . . . . . . . . . . . . . . . . . . . . . . . . 32
3.3.5. Date-Time . . . . . . . . . . . . . . . . . . . . . . 32
3.3.6. Duration . . . . . . . . . . . . . . . . . . . . . . 35
3.3.7. Float . . . . . . . . . . . . . . . . . . . . . . . . 36
3.3.8. Integer . . . . . . . . . . . . . . . . . . . . . . . 37
3.3.9. Period of Time . . . . . . . . . . . . . . . . . . . 37
3.3.10. Recurrence Rule . . . . . . . . . . . . . . . . . . . 38
3.3.11. Text . . . . . . . . . . . . . . . . . . . . . . . . 45
3.3.12. Time . . . . . . . . . . . . . . . . . . . . . . . . 47
3.3.13. URI . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.3.14. UTC Offset . . . . . . . . . . . . . . . . . . . . . 49
3.4. iCalendar Object . . . . . . . . . . . . . . . . . . . . 50
3.5. Property . . . . . . . . . . . . . . . . . . . . . . . . 51
3.6. Calendar Components . . . . . . . . . . . . . . . . . . . 51
3.6.1. Event Component . . . . . . . . . . . . . . . . . . . 52
3.6.2. To-Do Component . . . . . . . . . . . . . . . . . . . 55
3.6.3. Journal Component . . . . . . . . . . . . . . . . . . 57
3.6.4. Free/Busy Component . . . . . . . . . . . . . . . . . 59
3.6.5. Time Zone Component . . . . . . . . . . . . . . . . . 62
3.6.6. Alarm Component . . . . . . . . . . . . . . . . . . . 71
3.7. Calendar Properties . . . . . . . . . . . . . . . . . . . 76
3.7.1. Calendar Scale . . . . . . . . . . . . . . . . . . . 76
3.7.2. Method . . . . . . . . . . . . . . . . . . . . . . . 77
3.7.3. Product Identifier . . . . . . . . . . . . . . . . . 78
3.7.4. Version . . . . . . . . . . . . . . . . . . . . . . . 79
3.8. Component Properties . . . . . . . . . . . . . . . . . . 80
3.8.1. Descriptive Component Properties . . . . . . . . . . 80
3.8.1.1. Attachment . . . . . . . . . . . . . . . . . . . 80
3.8.1.2. Categories . . . . . . . . . . . . . . . . . . . 81
3.8.1.3. Classification . . . . . . . . . . . . . . . . . 82
3.8.1.4. Comment . . . . . . . . . . . . . . . . . . . . . 83
3.8.1.5. Description . . . . . . . . . . . . . . . . . . . 84
3.8.1.6. Geographic Position . . . . . . . . . . . . . . . 85
3.8.1.7. Location . . . . . . . . . . . . . . . . . . . . 87
3.8.1.8. Percent Complete . . . . . . . . . . . . . . . . 88
3.8.1.9. Priority . . . . . . . . . . . . . . . . . . . . 89
3.8.1.10. Resources . . . . . . . . . . . . . . . . . . . . 91
3.8.1.11. Status . . . . . . . . . . . . . . . . . . . . . 92
3.8.1.12. Summary . . . . . . . . . . . . . . . . . . . . . 93
3.8.2. Date and Time Component Properties . . . . . . . . . 94
3.8.2.1. Date-Time Completed . . . . . . . . . . . . . . . 94
3.8.2.2. Date-Time End . . . . . . . . . . . . . . . . . . 95
3.8.2.3. Date-Time Due . . . . . . . . . . . . . . . . . . 96
3.8.2.4. Date-Time Start . . . . . . . . . . . . . . . . . 97
3.8.2.5. Duration . . . . . . . . . . . . . . . . . . . . 99
3.8.2.6. Free/Busy Time . . . . . . . . . . . . . . . . . 100
3.8.2.7. Time Transparency . . . . . . . . . . . . . . . . 101
3.8.3. Time Zone Component Properties . . . . . . . . . . . 102
3.8.3.1. Time Zone Identifier . . . . . . . . . . . . . . 102
3.8.3.2. Time Zone Name . . . . . . . . . . . . . . . . . 103
3.8.3.3. Time Zone Offset From . . . . . . . . . . . . . . 104
3.8.3.4. Time Zone Offset To . . . . . . . . . . . . . . . 105
3.8.3.5. Time Zone URL . . . . . . . . . . . . . . . . . . 106
3.8.4. Relationship Component Properties . . . . . . . . . . 106
3.8.4.1. Attendee . . . . . . . . . . . . . . . . . . . . 107
3.8.4.2. Contact . . . . . . . . . . . . . . . . . . . . . 109
3.8.4.3. Organizer . . . . . . . . . . . . . . . . . . . . 111
3.8.4.4. Recurrence ID . . . . . . . . . . . . . . . . . . 112
3.8.4.5. Related To . . . . . . . . . . . . . . . . . . . 115
3.8.4.6. Uniform Resource Locator . . . . . . . . . . . . 116
3.8.4.7. Unique Identifier . . . . . . . . . . . . . . . . 117
3.8.5. Recurrence Component Properties . . . . . . . . . . . 118
3.8.5.1. Exception Date-Times . . . . . . . . . . . . . . 118
3.8.5.2. Recurrence Date-Times . . . . . . . . . . . . . . 120
3.8.5.3. Recurrence Rule . . . . . . . . . . . . . . . . . 122
3.8.6. Alarm Component Properties . . . . . . . . . . . . . 132
3.8.6.1. Action . . . . . . . . . . . . . . . . . . . . . 132
3.8.6.2. Repeat Count . . . . . . . . . . . . . . . . . . 133
3.8.6.3. Trigger . . . . . . . . . . . . . . . . . . . . . 133
3.8.7. Change Management Component Properties . . . . . . . 136
3.8.7.1. Date-Time Created . . . . . . . . . . . . . . . . 136
3.8.7.2. Date-Time Stamp . . . . . . . . . . . . . . . . . 137
3.8.7.3. Last Modified . . . . . . . . . . . . . . . . . . 138
3.8.7.4. Sequence Number . . . . . . . . . . . . . . . . . 138
3.8.8. Miscellaneous Component Properties . . . . . . . . . 139
3.8.8.1. IANA Properties . . . . . . . . . . . . . . . . . 140
3.8.8.2. Non-Standard Properties . . . . . . . . . . . . . 140
3.8.8.3. Request Status . . . . . . . . . . . . . . . . . 141
4. iCalendar Object Examples . . . . . . . . . . . . . . . . . . 144
5. Recommended Practices . . . . . . . . . . . . . . . . . . . . 147
6. Internationalization Considerations . . . . . . . . . . . . . 148
7. Security Considerations . . . . . . . . . . . . . . . . . . . 148
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 149
8.1. iCalendar Media Type Registration . . . . . . . . . . . . 149
8.2. New iCalendar Elements Registration . . . . . . . . . . . 152
8.2.1. iCalendar Elements Registration Procedure . . . . . . 152
8.2.2. Registration Template for Components . . . . . . . . 152
8.2.3. Registration Template for Properties . . . . . . . . 153
8.2.4. Registration Template for Parameters . . . . . . . . 153
8.2.5. Registration Template for Value Data Types . . . . . 154
8.2.6. Registration Template for Values . . . . . . . . . . 154
8.3. Initial iCalendar Elements Registries . . . . . . . . . . 155
8.3.1. Components Registry . . . . . . . . . . . . . . . . . 155
8.3.2. Properties Registry . . . . . . . . . . . . . . . . . 156
8.3.3. Parameters Registry . . . . . . . . . . . . . . . . . 158
8.3.4. Value Data Types Registry . . . . . . . . . . . . . . 159
8.3.5. Calendar User Types Registry . . . . . . . . . . . . 160
8.3.6. Free/Busy Time Types Registry . . . . . . . . . . . . 160
8.3.7. Participation Statuses Registry . . . . . . . . . . . 161
8.3.8. Relationship Types Registry . . . . . . . . . . . . . 161
8.3.9. Participation Roles Registry . . . . . . . . . . . . 162
8.3.10. Actions Registry . . . . . . . . . . . . . . . . . . 162
8.3.11. Classifications Registry . . . . . . . . . . . . . . 162
8.3.12. Methods Registry . . . . . . . . . . . . . . . . . . 163
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 163
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 164
10.1. Normative References . . . . . . . . . . . . . . . . . . 164
10.2. Informative References . . . . . . . . . . . . . . . . . 165
Appendix A. Differences from RFC 2445 . . . . . . . . . . . . . 167
A.1. New Restrictions . . . . . . . . . . . . . . . . . . . . 167
A.2. Restrictions Removed . . . . . . . . . . . . . . . . . . 167
A.3. Deprecated Features . . . . . . . . . . . . . . . . . . . 167
Notes:
Most of the Table Of Contents gives wrong page numbers.
===== Verifier notes =====
Indeed: the character table in Section 2.1, which appears at the top of page 8 in the RFC, appears to have been added during final editing, and has thrown off the page numbering for all sections beginning with 2.2.
Errata ID: 7332
Status: Verified
Type: Editorial
Publication Format(s) : TEXT
Reported By: Tobias Subklewe
Date Reported: 2023-02-04
Verifier Name: Francesca Palombini
Date Verified: 2024-01-16
Section 3.3.9 says:
The period start at 18:00:00 on January 1, 1997 and lasting 5 hours and 30 minutes would be: 19970101T180000Z/PT5H30M
It should say:
The period start at 18:00:00 on January 1, 1997 and lasting 5 hours and 30 minutes would be: 19970101T180000/PT5H30M
Notes:
I do not know if this is an editorial or technical issue.
If I understand the datetime value (Section 3.3.5) correct the last character should only be "Z" if the value is in UTC.
In the first example in section 3.3.9 UTC is explicitely mentioned but not in the second example.
Status: Reported (1)
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
Source of RFC: calsify (app)
Errata ID: 6316
Status: Reported
Type: Technical
Publication Format(s) : TEXT
Reported By: Ken Murchison
Date Reported: 2020-10-22
Section 3.8.5.1 says:
Value Type: The default value type for this property is DATE-TIME.
The value type can be set to DATE.
It should say:
Value Type: The default value type for this property is DATE-TIME.
The value type can be set to DATE. This property MUST have the same
value type as the "DTSTART" property contained within the
recurring component. Furthermore, this property MUST be specified
as a date with local time if and only if the "DTSTART" property
contained within the recurring component is specified as a date
with local time.
Notes:
EXDATE excludes a specific instance of a recurring event and therefore should have the same value type as DTSTART. This is analogous to RECURRENCE-ID which overrides a specific instance and has the same value type as DTSTART.
I will note however that there is iCalendar data in the wild with DTSTART;VALUE=DATE-TIME and EXDATE;VALUE=DATE. If this errata is rejected as incorrect, then a new errata should be opened with additional text describing how EXDATE;VALUE=DATE is supposed to be handled when DTSTART;VALUE=DATE-TIME. For instance, does EXDATE;VALUE=DATE exclude ALL instances of a FREQ=HOURLY recurrence on the given day?