seq.POSIXt: & DST (PR#1256)
On Fri, 11 Jan 2002 jutans@utans.u-net.com wrote:
Full_Name: Joachim Utans Version: 1.4.0 OS: NT4 sp4 Submission from: (NULL) (195.42.238.80) seq.POSIXt(..., by="day") apparently has problems steping over a change in daylight savings time; 2001-10-28 appears twice, the last day, 2001-10-30, is missing
Take a closer look. It is stepping by days, but that means by 24-hour
days. Look at it in GMT (there is no such time zone as GMT Daylight Time,
Bill Gates!)
z <- seq(as.POSIXct("2001-10-26"),as.POSIXct("2001-10-30"),by="day")
format(z, tz="GMT")
[1] "2001-10-25 23:00:00" "2001-10-26 23:00:00" "2001-10-27 23:00:00" [4] "2001-10-28 23:00:00" "2001-10-29 23:00:00" which is correct.
seq(as.POSIXct("2001-10-26"),as.POSIXct("2001-10-30"),by="day")
[1] "2001-10-26 00:00:00 GMT Daylight Time" "2001-10-27 00:00:00 GMT Daylight Time" "2001-10-28 00:00:00 GMT Daylight Time" [4] "2001-10-28 23:00:00 GMT Standard Time" "2001-10-29 23:00:00 GMT Standard Time"
Brian D. Ripley, ripley@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 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._