2011/7/19 Prof Brian Ripley <rip...@stats.ox.ac.uk>: >> but even this is dubious, since there is no year 0 AD. In Gregorian >> and Julian calendars, 1 BC continues directly into 1 AD. > > True, but these days we are ruled by ISO 8601:2004, which does define a year > 0 (the year before 1CE aka 1AD). See > http://en.wikipedia.org/wiki/0_(year) . > > It seems also to redefine the meaning of 'Gregorian calendar' calling what > you are referring to the 'BC/AD calendar system'. (Those who prefer BCE/CE > to BC/AD might note the usage of the latter in the definitive international > standard.)
The Date class has not been extended to support "0000-00-00"; rather, the origin argument of as.Date.numeric has been extended to allow "0000-00-00". There is no real difference between something like origin = "0000-00-00" and origin = "matlab", say. -- Statistics & Software Consulting GKX Group, GKX Associates Inc. tel: 1-877-GKX-GROUP email: ggrothendieck at gmail.com ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
