similar to: 'as.Date' conversion of classes POSIX*t (problem/feature)?

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" >

# pure replication code at end > # These work > > Sys.time() + NA [1] NA > as.POSIXlt(Sys.time(), "GMT") + NA [1] NA > > class(Sys.time() + NA) [1] "POSIXt" "POSIXct" > class(as.POSIXlt(Sys.time(), "GMT") + NA) [1] "POSIXt" "POSIXct" > > x <- Sys.time() + NA > y <- as.POSIXlt(Sys.time(),

When I do this (highly simplified example): plot(as.POSIXct(c("1984-01-01","1984-01-02")), c(1,2), col=2) I get a partially red (col=2) x-axis between and including the first and last tick marks. Otherwise ok. Only happens with POSIXct or POSIXlt dates. Also, POSIX dates cannot be used on the y-axis? POSIXlt gives an error, and POSIXct is unformatted. Bruce Using X11

I am finding that axis.POSIXct uses the local timezone for deciding where to put tic marks, even if the data being plotted are in another time zone. The solution is to use attr() to copy from the 'x' (provided as an argument) to the 'z' (used for the 'at' locations). I have pasted my proposed solution in section 1 below (as a diff). Then, in section 2, I'll put some

Hey R folks, i found some strange (to me) behaviour with chron to POSIXct conversion. The two lines of code result in two different results, on ewith the correct time zone, one without: library(chron) as.POSIXct(chron('12/12/2000'), tz = 'UTC') as.POSIXlt(chron('12/12/2000'), tz = 'UTC') Only the code below would give me a POSIXct object with the correct time

Full_Name: Allen McIntosh Version: 2.0.0 OS: RedHat 9.0 Submission from: (NULL) (67.80.175.118) The POSIX time printing routine gives strange results when asked to print a time that is exactly midnight: TZ=CST6CDT R -q --no-save > strptime("10/5/2004 00:00:01 CDT", "%m/%d/%Y %H:%M:%S %Z") [1] "2004-10-05 00:00:01" > strptime("10/5/2004 00:00:00

POSIXct/lt supports fractional seconds (see Sub-second Accuracy section of man page), but there seem to be some inconsistencies in their handling. Converting to POSIXlt and back does not give back the same time for times before the origin: > t0 <- as.POSIXct('1934-01-05 23:59:59.00001') > t0 [1] "1934-01-06 00:00:00 EST" # rounding issue, see below >

Full_Name: Arni Magnusson Version: 1.6.2 OS: Windows XP Submission from: (NULL) (210.48.49.68) Hi there. I'm experiencing unexpected behaviour from as.POSIXct: > as.POSIXct("1969-12-24") [1] "1969-12-23 23:00:00 New Zealand Standard Time" > as.POSIXlt("1969-12-24") [1] "1969-12-24" > as.POSIXlt("1969-12-24")+1 [1] "1969-12-23

Dear all, I have dataset which contains date and time in the format "yearmonthdayhour". I can read in these data correctly as follows: mydata <- read.csv("pm10_corine_gridcel_hourly_2011.csv", header = TRUE) mydata$date <- as.POSIXct(strptime(mydata$date, format = "%Y%m%d%H", tz="UTC")) However, midnight is defined as 24:00 in my original file (so

Dear R People: Here is an interesting question: >library(chron) >xt <- seq.dates(from="01/01/2004",by="days",length=5) >xt [1] 01/01/04 01/02/04 01/03/04 01/04/04 01/05/04 > #Fine so far >as.POSIXct(xt) [1] "2003-12-31 18:00:00 Central Standard Time" [2] "2004-01-01 18:00:00 Central Standard Time" [3] "2004-01-02 18:00:00 Central

Hello, the documentation for POSIXct and POSIXlt refers to the timezone keyword as "TZ". The functions expect "tz". BTW, is this where errors/ bugs should be reported? Cheers, Mike. ===== __________________________________________________ Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your desktop!

I have asked this question before, and received some suggestions for work-arounds that get the job done--and they are much appreciated. But I would still like to find out if I'm missing something, and whether there is a direct way using POSIXt functions (as.POSIXct, as.POSIXlt, strptime, in particular). I have environmental data collected once per minute. Here is a subset of 3 input

In trying to use as.Date(), I've come across the conversion of POSIXlt to POSIXct when a POSIXlt variable is included in a data frame: my_POSIX <- strptime(c("11-09-2006", "11-10-2006", "11-11-2006", "11-12-2006", "11-13-2006"), "%m-%d-%Y") str(my_POSIX) my_Date <- as.Date(my_POSIX) str(my_Date) data <- format(my_Date)

Dear list: working with date/times I have come across a problem that ISOdate and ISOdatetime are too slow on large vectors of data. I was surprised just until I looked at the implementation and the man page: "ISOdatetime and ISOdate are convenience wrappers for strptime". In other terms, they convert data to character representation first in order to create a POSIXlt object that is then

Hi all, I am testing R 4.0 and ran into an issue with timezones on Ubuntu Focal: converting a timestamp to another timezone results in NA: as.POSIXct(as.POSIXlt(Sys.time(), tz = "CET"), tz = "EST") This only happens on Ubuntu Focal, it seems to work fine on Ubuntu Bionic. I am the standard ubuntu docker image icw/ r-base from Dirk's ppa:edd/r-4.0 on both systems. Am I

Hello, I searched the archives but could not come to a solution. I have to two columns of information t_start_cdt looks like: > t_start_cdt[1:4] [1] "2003-07-09 11:02:25" "2003-07-09 11:10:25" "2003-07-09 11:30:25" [4] "2003-07-09 12:00:25" > class(t_start_cdt) [1] "POSIXt" "POSIXlt" t_end_cdt looks like: > t_end_cdt[1:4]

When I try to do linear interpolation between financial contracts with maturities on different dates in different months I have come across some behavior I haven't seen before. I have a data frame in R which is loaded from an access database so I can't provide a working example. It was loaded using this code: > dbPath <- "H:/pathToDB/DB.mdb" > channel <-

In attempting to build R using rpmbuild --rebuild R-2.1.0-0.fdr.2.fc3.src.rpm on a fairly up-to-date RedHat 9 system (that is, with patches installed through May 1 2004), it failed at the make check-all step. The problem was reproducible by going into the tests directory and make test-Segfault The last lines of the saved file no-segfault.Rout.fail are > > ## c.POSIXct : > >

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 >

I use POSIXct for datetimes. Is thee a timeAlign function that I can use where : align by year direction -1 ==> start of this year direction 1 ==> start of next year align by week direction -1 ==> date on last sunday direction 1 ==> date on next sunday align by day direction -1 ==> time at past midnight direction 1 ==> time at this comming