[Ietf-calsify] working group last call commentsfor draft-ietf-calsify-rfc2445bis-07.txt

Eliot Lear lear at cisco.com
Thu Sep 27 07:55:25 PDT 2007


Nigel,

Please wade through the below.  Would others please comment as well?



>
>> Nigel's addition is not substantial.  It is repeating what is
>> already specified in section 4.6.5 "Time Zone Component" of
>> RFC 2445, that is:
>>
>>     The mandatory "DTSTART" property gives the effective onset date and
>>     local time for the time zone sub-component definition. "DTSTART" in
>>     this usage MUST be specified as a local DATE-TIME value.
>>
>> I'm not convinced we should repeat this information.
>>
>> No change done.
>>     
>
> The existing text has this:
>
>       ...  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. .......
>
> One of my objectives was to get rid of the second sentence, as I don't think
> it adds anything, and in the context of the whole paragraph it's confusing
> to know what the second sentence is even refering to.  If this second
> sentence is to stay could someone please explain what it adds?
>
> My second objective was indeed to correlate more fully the relationship
> between DTSTART and UNTIL as it says in 4.6.5.  The start of the paragraph
> has described this relationship in detail for DTSTART and UNTIL under normal
> circumstances, but then goes on to talk about the behaviour within the
> STANDARD/DAYLIGHT components.  I think either it should leave all the
> discussion of it's behaviour within STANDARD/DAYLIGHT to section 4.6.5, or
> complete the discussion by saying, as I had suggested, that UNTIL is always
> date with UTC time and DTSTART is always date with local time.
>
> My third objective was to cleanup the language of the last sentence.
>
> So please can we have either:
>
>        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
>  +      rule part MUST always be specified as a date with UTC time, with the
>  +      "DTSTART" always represented as a date with local time.  If the
> UNTIL
>  +      and COUNT rule parts are not
>        present, the "RRULE" is considered to repeat forever.
>
> Or:
>
>        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
> +       the UNTIL rule part MUST be specified as a date with UTC time.
> +       If the UNTIL and COUNT rule parts are not
>        present, the "RRULE" is considered to repeat forever.
>
>   

Bernard will propose some cleaned up text to address your issues.

>>>> WRT to the text below I think we should either:
>>>> - Say BYSETPOS is only valid with Weekly, Monthly, Yearly rules,
>>>> - Specify what the "interval" for daily, hourly, minutely, secondly
>>>> means.
>>>> - Drop the new text, as I think the example is sufficient illustration.
>>>> - Change the example to illustrate what obscurity it was that lead to
>>>>         
> the
>   
>>>> need for the new text.
>>>>
>>>> My vote would be to drop some of the new text to become:
>>>>
>>>>       The BYSETPOS rule part specifies a COMMA character (US-ASCII
>>>>       decimal 44) separated list of values which corresponds to the nth
>>>>       occurrence within the set of recurrence instances specified by
>>>>         
> the
>   
>>>>       rule.  BYSETPOS operates on a set of recurrence instances in one
>>>> -      interval of the recurrence rule.  For a WEEKLY rule, the
>>>>         
> interval
>   
>>>> -      is one week, for a MONTHLY rule, one month, and for a YEARLY
>>>>         
> rule,
>   
>>>> -      one year.  Valid values are 1 to 366 or -366 to -1.  It MUST
>>>>         
> only
>   
>>>> +      interval of the recurrence rule.
>>>> +      Valid values are 1 to 366 or -366 to -1.  It MUST only
>>>>       be used in conjunction with another BYxxx rule part.  For example
>>>>       "the last work day of the month" could be represented as:
>>>>
>>>>         FREQ=MONTHLY;BYDAY=MO,TU,WE,TH,FR;BYSETPOS=-1
>>>>
>>>>       Each BYSETPOS value can include a positive (+n) or negative (-n)
>>>>       integer.  If present, this indicates the nth occurrence of the
>>>>       specific occurrence within the set of occurences specified by the
>>>>       rule.
>>>>         
>>> Substantial.
>>>       
>> Not changed.
>>     
>
> I think this is important, as currently we have it's an inconsistent level
> of specification, which I think leaves it vague what BYSETPOS means with
> daily, hourly, minutely, secondly.  Could people please comment/vote?
>   

There seems to be agreement.  Bernard will propose text.


>   
>>>> The phrase "special expand" is mentioned nowhere else in the document.
>>>>         
> I
>   
>>>> think the concept was better expressed by my suggestion from the 29th
>>>>         
> May.
>   
>>>> You merge the "Expand" cells in the Yearly/Monthly columns to
>>>>         
> illustrate
>   
>>>> that each creates a set, and when taken together it's the union of the
>>>>         
> sets.
>   
>>>> Also even with a numeric modifier on ByDay, it's still the case that
>>>> Monthly/Yearly + BYDAY will expand, and while it's true that numeric
>>>> modifiers on ByDay with yearly rules requires attention, I think it's
>>>> adequately dealt with in the paragraphs above on ByDay.  So I'd make
>>>>         
> it:
>   
>>>> -      BYDAY has some special behaviour depending on the FREQ value and
>>>> -      this is described in separate notes below the table.
>>>>
>>>>    +----------+--------+--------+-------+-------+------+-------+------+
>>>>    |          |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|
>   
>>>> -
>>>>         
> +----------+--------+--------+-------+-------+------+-------+------+
>   
>>>> +   |BYMONTH   |Limit   |Limit   |Limit  |Limit  |Limit |Limit  |
>>>>         
> |
>   
>>>> +   +----------+--------+--------+-------+-------+------+-------+
>>>>         
> +
>   
>>>> +   |BYWEEKNO  |N/A     |N/A     |N/A    |N/A    |N/A   |N/A    |
>>>>         
> |
>   
>>>> +   +----------+--------+--------+-------+-------+------+-------+
>>>>         
> +
>   
>>>> +   |BYYEARDAY |Limit   |Limit   |Limit  |N/A    |N/A   |N/A
>>>>         
> |Expand|
>   
>>>> +   +----------+--------+--------+-------+-------+------+-------+
>>>>         
> +
>   
>>>> +   |BYMONTHDAY|Limit   |Limit   |Limit  |Limit  |N/A   |       |
>>>>         
> |
>   
>>>> +   +----------+--------+--------+-------+-------+------+Expand +
>>>>         
> +
>   
>>>> +   |BYDAY     |Limit   |Limit   |Limit  |Limit  |Expand|       |
>>>>         
> |
>   
>>>> +
>>>>         
> +----------+--------+--------+-------+-------+------+-------+------+
>   
>>>>    |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.
>>>>
>>>> +      In YEARLY rules, BYMONTH, BYWEEKNO, BYYEARDAY, BYMONTHDAY and
>>>>         
> BYDAY work
>   
>>>> +      together to expand the recurrence set.  Each on their own will
>>>>         
> specify
>   
>>>> +      a range of valid instances, and when used in combination it is
>>>>         
> the union
>   
>>>> +      of all ranges that create the required recurrence set.  So for
>>>>         
> example
>   
>>>> +      in a YEARLY rule BYDAY=MO will mean every Monday, and
>>>>         
> BYMONTHDAY=1 will
>   
>>>> +      mean the first of every month, so when used together they mean
>>>>         
> the first of
>   
>>>> +      every month, but only when it's a Monday.  It would not mean on
>>>>         
> the first
>   
>>>> +      of every month and also on every Monday.  Likewise in MONTHLY
>>>>         
> rules,
>   
>>>> +      BYMONTHDAY and BYDAY work together to expand the recurrence set.
>>>>
>>>>         
>>> Substantial and editorial.  The combining of boxes is editorial.
>>>       
>> Not changed for now.
>>
>>     
>
> Rather than give you lots more text to read, can I just urge you to (re)read
> the text above and provide opinions.  I think recurrence is the most
> complicated part of iCalendar, and think it's worth crafting the addition of
> the new table just a little more.
>   

Would people please comment on Nigel's proposed change?

Thanks!

Eliot


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