[Rd] So-called 'bug' reports PR#8102 and PR#8103

Prof Brian Ripley ripley at stats.ox.ac.uk
Wed Aug 31 12:40:42 CEST 2005

Neither of these have reached me on R-devel (and only PR#8103 is on the 
archive), and they seem to be the same error although neither mentions the 
other.  That's 'odd', to quote one of them.

"EDT" is not a valid POSIX timezone (but, say, EST5EDT is).  R's docs are 
quite clear that what happens with invalid inputs is system-specific. 
(Windows seems often to run home to PST8PDT.)  You can have timezones 
without DST, but not one permanently in DST.

In short, these were user errors compounded by unhelpful error-recovery by 
the OS the users were using.

As to why tm + 3600 and tm + c(0, 1) * 3600 differ: one time is in one 
timezone, but two can be in different timezones so they must be handled 
differently.  This is handled slightly differently in the R-devel version, 
which both the posting guide and the FAQ do ask you to try out (as well as 
consulting the NEWS file which has a relevant entry).

Next time, please show some consideration for those who have to clear up 
after you, and do as we ask in the posting guide and FAQ.

Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

More information about the R-devel mailing list