ietf-mta-filters
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Re: variables: open issue a) date variables

2003-05-02 20:36:55

[Ned Freed]:

  There definitely needs to be a way to specify a day of the week. I
  really don't care if it is 1/2/3/4 or mon/tue/wed or whatever, but
  it needs to be there because people want to take certain actions
  based on the day of week.
  
  FWIW, RFC 2445 uses
  
  weekday    = "SU" / "MO" / "TU" / "WE" / "TH" / "FR" / "SA"

numeric values seem more versatile, but textual values make for more
readable scripts.

  Beyond that, an iso8601 option would be useful for checking
  boundaries in a single operation. RFC 3339 can be referenced for
  this.

thanks, I hadn't read that RFC (shame on me), but I don't quite get
the reference?  do you mean a variable containing the complete
"2003-05-03T05:03:12.00+02:00" ?  (I think I would leave out the time
zone for this application, actually.)

  > for the weekday, while 0..6 with 0 meaning Sunday may seem alien
  > to many users (including me :), at least the information is
  > available in an unambigious fashion.
  
  If you use 1/2/3 you _are_ using the Islamic days of the week ;-)

well, I'm a member of the The Net Atheists, but on the seventh day He
resteth or something like that, so it always struck me as odd to
number Sunday as the first day of the week.  but I digress ;-)

  > so my suggestion is to augment the list with the following:
  >
  >   ${weekday}   (0..6)       %w: 0 is Sunday
  >   ${week}      (01..53)     %V: week number according to ISO 8601
  
  These are both fine as far as I'm concerned.

now I'm not so sure.  RFC 3339 follows ISO 8601 and uses

   date-wday       =  DIGIT  ; 1-7  ; 1 is Monday, 7 is Sunday

  >   ${isoyear}   (0000..9999) %G: year number according to ISO 8601.
  >                                 needed since Jan 1 2000 is in week 52
  >                                 of 1999
  
  The last doesn't necessarily follow. If you're using week numbers
  you may not care about the specific year.

I see two main uses for ${week}.  one is vacation message: "I'll be
out of town during week 45 and 46".  the other is for fileinto, and
then we need ${isoyear} to get a strict ordering.

the problem with the former use is that US weeks doesn't match ISO
weeks.  we Europeans will be fine (I think -- Norwegians for sure ;-).

-- 
Kjetil T.