similar to: Date operations

Hi all, I'm having difficulty converting a 'dates' object to a POSIXct object: testDATES<-c(35947,35971,36004,36008,36053,36066) testDATES<-chron(dates=testDATES, format = c(dates = "m/d/y"), origin=c(month = 12, day = 30, year = 1899)) >[1] 06/01/98 06/25/98 07/28/98 08/01/98 09/15/98 09/28/98 > as.POSIXct(testDATES) [1] NA NA NA NA NA NA

Hello!! I need some help! I tried everything, but nothing worked! I have a vector c with dates in it, in the format "2004-04-01" and i need to convert it in the form "04/01/2004" or "01/04/2004" ! How can i do that?? Thanks Bye Martina --

Hi all; I've already send a similar e-mail to the list and Prof. Brian Ripley answered me but my doubts remain unresolved. Thanks for the clarification, but perhaps I wasn't clear enough in posting my questions. I've got a postgres database which I read into R. The first column is Timestamp with timezone, and my data are already in UTC format. An 'printed' extract of R

I am a beginner in R with a background in SAS. Are there built-in R methods of reading dates for calculating elapsed days between two calendar dates? If so, are there any examples I can browse? Thanks in anticipation. John Byrne. Lecturer in Information Systems. Australian Catholic University.

Hi, I have a whole bunch of data, which looks like: 15/03/2003 10:20 1 15/03/2003 10:21 0 15/03/2003 12:02 0 16/03/2003 06:10 0 16/03/2003 06:20 0.5 16/03/2003 06:30 0 16/03/2003 06:40 0 16/03/2003 06:50 0 18/03/2003 20:10 0.5 etc. (times given on a 24 hour clock) and goes on for years. I have some code:

Hi all I am a relatively new R user so please excuse this question if it has been covered some where else, just tell me where to find it. I have a simulation model that out puts dates in a standard dd/mm/yy format R reads this as a factor and I cant find anything that will allow me to convert them to a date. In S+ I have used a chron() function that required you to specify the format of the

I'm having problems entering dates and times around when daylight savings time starts. If I type (on R 1.8.1 on Gentoo Linux) > ISOdatetime(2004,4,4,0:4,0,0,"GMT") [1] "2004-04-03 19:00:00 EST" "2004-04-03 20:00:00 EST" [3] "2004-04-03 22:00:00 EST" "2004-04-03 22:00:00 EST" [5] "2004-04-03 23:00:00 EST" Giving the times

Dear all, I have a variable 'x' like that: > x [1] "2005-09-01" Here, 2005 represents year, 09 month and 01 day. Now I want to create three variables naming: y, m, and d such that: y = 2005 m = 09 d = 01 can anyone tell me how to do that? Regards, [[alternative HTML version deleted]]

To Whom It May Concern: The following appears to be a bug in the way POSIXct dates are formated. The example is forced, but occurs naturally when importing Excel type dates (where fractional part is fraction of a day) and small rounding errors result. As shown, looking at the POSIXct class, it looks as if both times are 16:11:03 (truncation) Looking at as.numeric.POSIXct, it looks as if

I've been trying to understand the as.Date functionality and I have a date and time stamp field that looks like this: "Tue Sep 15 09:22:09 -0600 2009" and I need to turn it into an R Date object for analysis. Simple date conversions I have down, no problem: > adate = c("7/30/1959") > as.Date(adate,"%m/%d/%Y") [1] "1959-07-30" > But when it

This is mostly a RFC [but *not* about the many extra packages, please..]: Noticing to my chagrin how my students work in a project, googling for R code and cut'n'pasting stuff together, accumulating this and that package on the way all just for simple daily time series (though with partly missing parts), using chron, zoo, lubridate, ... all for things that are very easy in base R *IF*

I have some questions and comments on timezones. Problem 1. # get current time in current time zone > (now <- Sys.time()) [1] "2003-07-29 18:23:58 Eastern Daylight Time" # convert this to GMT > (now.gmt <- as.POSIXlt(now,tz="GMT")) [1] "2003-07-29 22:23:58 GMT" # take difference > now-now.gmt Time difference of -5 hours Note that the difference

I know that this is correct: library(chron) x = dates("01-03-04", format="d-m-y", out.format="day mon year") print(x) It gives me the string "01 Mar 2004" which is correct. I also know that I can say: print(day.of.week(3,1,2004)) in which case he says 1, for today is monday. My question is: How do I combine these two!? :-) I have a

Hello, I've encountered the need to cut some chron objects of the form: R> mychron <- chron(sort(runif(10, 0, 10))) R> mychron [1] (01/01/70 16:36:20) (01/02/70 00:08:46) (01/03/70 16:54:49) [4] (01/04/70 06:45:00) (01/07/70 06:21:24) (01/07/70 18:28:44) [7] (01/08/70 00:47:05) (01/08/70 05:11:44) (01/10/70 01:07:53) [10] (01/10/70 17:46:53) into arbitrary (e.g. a given number

Times from seq.POSIXt come out wrong in AEST timezone around Feb 29 every leap year before 1970 (on Windows XP). According to help(DateTimeClasses), this is handled by "our own C code". > x <- as.POSIXct("1968-02-27") # tz="AEST" > x.gmt <- as.POSIXct("1968-02-27", tz="GMT") > data.frame( GMT=seq(x.gmt, by="day",

If I take the following simple data: YEAR MONTH DAY WEIGHT.KG 2003 10 6 1.2 2003 10 12 1.2 2003 10 16 1.3 and format the date data and plot it: dates <- strptime(paste(DAY,MONTH,YEAR),"%d%m%Y") plot(c(min(dates),max(dates)),c(0,max(WEIGHT.KG)), xlab="Date",ylab="Weight (kg)",type="n") lines(dates,WEIGHT.KG) points(dates,WEIGHT.KG) I find that the

Dear useRs, How come the first attempt to sort a POSIXt vector fails (Error: non-atomic type in greater), while the second succeeds? (Code inserted below.) The documentation says that POSIXt is used to allow operations such as subtraction, so I'd expect sorting to work. Is this perhaps an OS issue? (I run R 2.0.1 on Win xp.) Thank you, b. #------------code test <- c("2005-02-08

Hi .. i am a beginner in R I have data in the format of date 04/27/11 04/27/11 04/30/11 04/30/11 05/03/11 05/03/11 05/04/11.... Now i want to plot the data something like this on x-axis... ------------------ 27 28 29 30 1 2 3 4 April May I also wanted to know how to place a "*" when a date is missing from the data.. my

It seems is.weekend() is unsure ? # Start R 1.9.0 with --vanilla on windows xp # load package chron > table(is.weekend(sapply(1:100, function(i){Sys.sleep(0.05);Sys.time()}))) FALSE TRUE 68 32 > date() [1] "Wed May 26 11:18:56 2004" > version _ platform i386-pc-mingw32 arch i386 os mingw32 system i386, mingw32

Hola a todos: Debe de ser una tontería, pero no consigo saber porque la siguiente linea no devuelve la fecha actual: as.Date(as.numeric(Sys.time())) He hecho esa prueba porque no consigo pasar un numero convertido a partir de una fecha y modificado a fecha de nuevo. Gracias por adelantado. Un saludo, Alberto. [[alternative HTML version deleted]]