Prof Brian Ripley <[EMAIL PROTECTED]> writes:
> > %W seems to be what is known as "ISO dates" (week starts on Monday),
> > except that
> >
> >> strftime(as.POSIXlt(as.Date("2005-01-01")), "%U")
> > [1] "00"
> >
> > should be week 53, 2004 according to my printed calendar, and emacs
> > calendar-mode too.
>
> I _did_ say
>
> >> That's nothing like as easy, as it is not well-defined.
>
> The POSIX definition is
>
> %U
> Replaced by the week number of the year as a decimal number [00,53].
> The first Sunday of January is the first day of week 1; days in the
> new year before this are in week 0.
>
> %W
> Replaced by the week number of the year as a decimal number [00,53].
> The first Monday of January is the first day of week 1; days in the
> new year before this are in week 0.
>
> so it is doing what it is documented to do. I'd take POSIX as more
> definitive than Emacs ....
But not more definitive than the ISO standard, I hope. There are
probably more that 1e8 calendars printed each year according that one.
The two routines are just not doing the same thing. Calendar-mode goes
by the ISO standard, strftime by POSIX definitions. Of course it all
depends on what the user actually wanted.
--
O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B
c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K
(*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918
~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907
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