similar to: as.POSIXct before and after 1970

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

Under platform i686-pc-linux-gnu arch i686 os linux-gnu system i686, linux-gnu status major 1 minor 6.1 year 2002 month 11 day 01 language R > x <- strptime(c('10/10/1969','12/31/2002'),format='%m/%d/%Y')

> x<-as.POSIXct("1970-1-1", tz="UTC")-.5 > y<-as.POSIXct("1970-1-1", tz="UTC")+.5 > x==y [1] FALSE # of course but x and y "appear" to be the same when formatted, even with extra precision: > format(x, format="%Y-%m-%d %H:%M:%OS2") [1] "1970-01-01 00:00:00.50" > format(y, format="%Y-%m-%d

It took me some time to realize this annoying behavior was coming from lubridate. Perhaps this behavior is unexpected a result of cursory knowledge of it.... ## The expected behavior > sometimes=c(0,1,2,3)*60*60*24 > as.POSIXct( sometimes, origin='1970-01-01', tz='GMT') [1] "1970-01-01 GMT" "1970-01-02 GMT" "1970-01-03 GMT" "1970-01-04

A user here noticed the following difference between Linux and Windows versions of R-2.15.3 (and R-3.0.0, I think) when using times within a second of the end of 1969: f <- function (sec = -1) { x1 <- as.POSIXct(c(2 * sec, sec, 0), origin = "1970-01-01", tz = "UTC") x2 <- as.POSIXlt(x1) x3 <- as.POSIXct(x2, origin = "1970-01-01", tz =

Dear R developers, I have found a minute bug in R-3.5.1 (Windows version), about how times not an exact number of seconds are displayed. > as.POSIXct("1969-01-01 01:00")+0.3 [1] "1969-01-01 01:00:01 CET" > as.POSIXct("1970-01-01 01:00")+0.3 [1] "1970-01-01 01:00:00 CET" So for 1969, adding 0.3 of a second means you round UP, for 1970 you round DOWN.

There is something wrong, I think, with the date-time conversion from a numeric value if you use Central European Time (CET) as timezone. Examples from R: If I use the GMT time zone it is OK, I get the same time back from as.POSIXct as I entered > as.POSIXct(as.numeric(strptime("30/01/2012 13:00:00", format="%d/%m/%Y >

Hello: What is the recommended method for retaining the tzone attributes when concatonating POSIXct objects? > (d1 <- ISOdate(1970,1,1)) # Sets the tzone attribute = GMT [1] "1970-01-01 12:00:00 GMT" > (d1.2 <- c(d1, d1)) # c(..) strips the tzone attribute, displays in the time zone of the operating system [1] "1970-01-01 04:00:00 PST" "1970-01-01

The following three calls all produce the same result (my machine is in EST): > as.POSIXct(0, tz="", origin=ISOdatetime(1970,1,1,10,0,0)) [1] "1970-01-01 10:00:00 EST" > as.POSIXct(0, tz="EST", origin=ISOdatetime(1970,1,1,10,0,0)) [1] "1970-01-01 10:00:00 EST" > as.POSIXct(0, tz="GMT", origin=ISOdatetime(1970,1,1,10,0,0)) [1]

A sample of the data I have is: > head(sensor) logged_on accx accy accz compassx compassy compassz gyrox gyroy gyroz 1 1326561428000 -0.4602 0.8346 0.0936 0.145508 -0.350586 0.259766 59.617390 28.521740 59.617390 2 1326561428050 -0.4212 1.0452 0.1326 0.219727 -0.321289 0.241211 88.695656 27.478260 88.695656 3 1326561428100 -0.2496 1.3416 0.2886 0.214844 -0.326172

Greetings - I'm battling POSIXct, as per the code below. My input is actually an XL file, but the weird results below correctly model what I am seeing in my program. Before I punt and use lubridate or timeDate, could anyone please help me understand why POSIXct forces my variable back to GMT? I suspect that I'm not properly coding the tzone value, but it does not throw an

R-devel: Some very inconsistent behavior, that I can't seem to find documented. Sys.setenv(TZ="GMT") str(unclass(strptime("1969-12-31 23:59:59","%Y-%m-%d %H:%M:%S"))) List of 9 $ sec : num 59 $ min : int 59 $ hour : int 23 $ mday : int 31 $ mon : int 11 $ year : int 69 $ wday : int 3 $ yday : int 364 $ isdst: int 0 - attr(*, "tzone")= chr

Hi, How do I convert a numeric value indicating the time since 1970, back into a POSIXct class object? I have tried format.POSIXct and as.POSIXct without success. For example > ccc [1] "1945-01-01 15:00:00 MDT" > ddd<- as.numeric(ccc); > ddd [1] -788842800 > format.POSIXct(ddd) Error in format.POSIXct(ddd) : wrong class > as.POSIXct(ddd) Error in

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

Hi all, In what encoding does format.POSIXct return its output? It doesn't seem to be utf-8: Sys.setlocale("LC_ALL", "Japanese_Japan.932") times <- c("1970-01-01 01:00:00 UTC", "1970-02-02 22:00:00 UTC") ampm <- format(as.POSIXct(times), format = "%p") x <- gsub(">", "*", paste(ampm, collapse =

Hello I have trouble getting my original datetime back see below. I hope I am missing something. Please help. > tt <- as.POSIXct("2011-01-07 07:49:13", tz="EST") > tt [1] "2011-01-07 07:49:13 EST" > ttn <- as.numeric(tt) > ttn [1] 1294404553 > tt <- as.POSIXct(ttn,origin='1970-01-01',tz="EST") > tt [1] "2011-01-07

First, the reproducable example, showing how converting from character to POSIXct to character changes the milliseconds in the first time stamp though not in the second: > as.POSIXct('2010-06-03 9:03:58.324') [1] "2010-06-03 09:03:58.323 PDT" > as.POSIXct('2010-06-03 9:03:58.325') [1] "2010-06-03 09:03:58.325 PDT" This seems to be due to truncation of

Hi, I have a list/data.frame 'pk' of POSIXct dates, and I'd like to extract the hour for each row. I know that if I have an individual POSIXct object, I can extract the hour by converting to a new object with: new.lt <- as.POSIXlt(<single POSIXct object>) new.lt$hour But I can't figure out how to apply this for a list of such dates in a vectorized form. I can write a

A tiny nit-pick: Seems to me that end date = NA would mean the event has not yet ended, whilst Inf would mean that the event is known to never terminate, ie: an eternal fact, or physical law. On Fri, Apr 28, 2023 at 10:12?AM Davis Vaughan via R-devel < r-devel at r-project.org> wrote: > Hi all, > > I noticed that `range.default()` has a nice `finite = TRUE` argument, > but it

Hi, I encountered the behavior, that the duplicated method for data.frames gives "false positives" if there are columns of class POSIXct with a clock shift from DST to standard time. time <- as.POSIXct("2012-10-28 02:00", tz="Europe/Vienna") + c(0, 60*60) time [1] "2012-10-28 02:00:00 CEST" "2012-10-28 02:00:00 CET" df <-