similar to: number of days

The interface for dates in R is a little confusing to me. I want to create a vector of Date objects from vectors of years, months, and days. One solution I found is: years <- c(1991, 1992) months <- c(1, 10) days <- c(1, 2) dates <- as.Date(ISOdate(years, months, days)) But, in this solution the ISOdate function converts the vectors into characters, which can cause serious

Hi WizaRds, What is the "standard" way to get the day of the week from a date such as as.Date("2006-12-01")? It looks like fCalendar has some functions but this requires a change in the R locale to GMT. Is there another way? Thanks! Jack. --------------------------------- Be a PS3 game guru. [[alternative HTML version deleted]]

Full_Name: Alec Stephenson Version: 1.6.0 OS: linux Submission from: (NULL) (148.88.138.5) Appears to be a sign error in as.POSIX(lt/ct) > library("chron") The following is fine, with default origin. > tmp <- chron(1:2, origin = c(1,1,1970)) > as.POSIXlt(tmp) [1] "1970-01-02 01:00:00 GMT" "1970-01-03 01:00:00 GMT" These are not. > tmp <-

Hello r-help, I'm trying to split a character vector of dates of the form "dd-mmm-yy" into component days, months and years. But > library(chron) > testdate<-as.POSIXlt(strptime("17-Sep-98","%d-%b-%y")) > testdate [1] "1998-09-17" > months(testdate) [1] "September" # which is fine, but for days and years I get >

Hi list, I'm trying to turn a date into something productive. (Not what you may be thinking....) I want three functions so I could take a "date" object and get the day of week, month, and year from it. xx <- as.Date("2006-01-05") month(xx) equal 1 day(xx) equal 5 year(xx) equal 2006 I'm aware of the weekdays() and months() functions in the base package. But

Dear all, I have a question related to the POSIXlt function in R. I have a set of dates and times, for exmaple: startx <- as.POSIXct("2011-01-01 00:00:00") finx <- as.POSIXct("2011-12-31 00:00:00") daysx<- seq(startx, finx, by="24 hours") I want to change the dates of all the days falling on a Saturday to the next working day (i.e. Monday). So I

Hi R-users, What is the best way to achieve a table which contains all days and months between years 2007-2020? I would like to calculate number of days in each month within those years (to data frame). Regards, Lauri [[alternative HTML version deleted]]

Hi, Let say I have a date variable like this: structure(1243792800, class = c("POSIXct", "POSIXt"), tzone = "GMT") [1] "2009-05-31 18:00:00 GMT" How can I make it 10 days prior, so: [1] "2009-05-21 18:00:00 GMT" I'm randomly selecting dates from a list and want a second value a set # of days either before or after. Thanks ahead of time.

Hi R-users, I have a data set like this (first ten rows): id patient_id date code class eala ID1564262 1562 6.4.2006 12:00 5555 1 NA ID1564262 1562 6.4.2006 12:00 5555 1 NA ID1564264 1365 14.2.2006 14:35 5555 1 50 ID1564265 1342 7.4.2006 14:30 2222 2 50 ID1564266 1648 7.4.200614:30 2222 2 50 ID1564267 1263 10.2.2006 15:45 2222 2 10 ID1564267 1263 10.2.200615:45 3333 3 10 ID1564269 5646

I've always found the chron library to be useful for tasks like this: > x <- round(runif(10)*100000, digits=0) > y <- as.Date(x, origin="1970-01-01") > library(chron) > days(y) [1] 7 25 26 25 10 24 1 31 12 8 31 Levels: 1 < 2 < 3 < 4 < 5 < 6 < 7 < 8 < 9 < 10 < 11 < 12 < 13 < ... < 31 Notice that it returns the days as

Hello, I've come across a problem in developing a set of custom functions to calculate the number of hours of daylight at a given latitude, and the number of days a date precedes or secedes the summer solstice. I discovered an inconsistency concerning leap years between my derived values and those from the US naval databases. It seems as far as I can figure that my inconsistency arises either

I tried the code that Richard O'Keefe posted last week, to wit: library(chron) ymd.to.POSIXlt <- function (y, m, d) as.POSIXlt(chron(julian(y=y, x=m, d=d))) n <- 100000 y <- sample(1970:2004, n, replace=TRUE) m <- sample(1:12, n, replace=TRUE) d <- sample(1:28, n, replace=TRUE) system.time(ymd.to.POSIXlt(y, m, d)) [1] 8.78 0.10

Hi all, I ran into a segfault while playing with dates. $ R --no-init-file ... > library(lubridate); d=as.POSIXlt(floor_date(Sys.time(),"year")); d$zone=NULL; d$zone=""; d Attaching package: ?lubridate? The following object is masked from ?package:base?: date Warning message: package ?lubridate? was built under R version 3.4.0

The return value of Sys.time() today with a timezone of US/Eastern is unchanged between 4.0.3-patched and devel, but on devel the following test fails all.equal(x, as.POSIXlt(x)) with x = Sys.time() This means that devel does not complete make tests (failure on tests/reg-tests-2.R) It is entirely possible that it is an error on my end, I use export TZ="US/Eastern" but I have been

Full_Name: Erich Neuwirth Version: 2.3.1 OS: Windows XP, Linux Submission from: (NULL) (131.130.135.167) Converting Sys.Date() to a POSIX compliant time type in different ways produces inconsistent results: > Sys.date() [1] "2006-09-01" > as.POSIXct(Sys.Date()) [1] "2006-09-01 02:00:00 CEST" > as.POSIXlt(Sys.Date()) [1] "2006-09-01" >

Dear R users, Given this data: x <- seq(1,100,1) dx <- as.POSIXct(x*900, origin="2007-06-01 00:00:00") dfx <- data.frame(dx) Now to play around for example: subset(dfx, dx > as.POSIXct("2007-06-01 16:00:00")) Ok. Now for some reason I want to extract the datapoints between hours 10:00:00 and 14:00:00, so I thought well: subset(dfx, dx >

>>>>> Joshua Ulrich <josh.m.ulrich at gmail.com> >>>>> on Tue, 6 Dec 2016 09:51:16 -0600 writes: > On Tue, Dec 6, 2016 at 6:37 AM, <frederik at ofb.net> wrote: >> Hi all, >> >> I ran into a segfault while playing with dates. >> >> $ R --no-init-file >> ... >> >

Dear all, I have just detected what seems a minor inconsistence with data types. If one unlists a POSIXlt time with GMT zone gets a numeric vector, since the POSIXlt list has no `zone` element, while if one unlists a POSIXlt time with a non GMT zone (also non specifying tz if the Sys.timezone is not GMT) gets a character vector due to including the `zone` element. > x <-

Apparently, as.POSIXlt takes one o'clock as the start of the day : > as.POSIXlt(0,origin="1970-01-01") [1] "1970-01-01 01:00:00 CET" > as.POSIXlt(0,origin="1970-01-01 00:00:00") [1] "1970-01-01 01:00:00 CET" > as.POSIXlt(0,origin="1970-01-01 23:59:59") [1] "1970-01-02 00:59:59 CET" Cheers -- Joris Meys Statistical

Hi, Does anybody know why get I this kind of strange situation: Browse[2]> hcEnd [1] "2009-03-29 06:30:00" Browse[2]> class(hcEnd) [1] "POSIXlt" "POSIXt" Browse[2]> is.na(hcEnd) [1] TRUE This issue is the source of my all issues in my program, Thanks for your help -- View this message in context: