similar to: lubridate, as.POSIXct and a vector of times: bug or feature??

Dear all, I wish to create a POSIXct variable from date and time variables using the ymd_hm function in package lubridate. In some cases data for time is missing, which causes a problem for ymd_hm. I wish to find a smooth way to handle this. # Some example data: x <- data.frame(date = c("2011-09-22", "2011-07-28"), time = c("15:00", NA)) x # paste date and

Can someone, please, explain the difference in as.POSIXct results before 1970 and on and after 1970 as illustrated below. After 1970, the use of 'EST' or "EST+5EDT' as the timezone does not affect the result of asPOSIXct, but before 1970 on 10/28 the results are different. > as.POSIXct('1970-10-29', tz='EST')+1 [1] "1970-10-29 00:00:01 EST" >

#lubridate lubridate makes it easier to work with dates and times by providing functions to identify and parse date-time data, extract and modify components of a date-time (years, months, days, hours, minutes, and seconds), perform accurate math on date-times, handle time zones and Daylight Savings Time. lubridate has a consistent, memorable syntax that makes working with dates less frustrating.

#lubridate lubridate makes it easier to work with dates and times by providing functions to identify and parse date-time data, extract and modify components of a date-time (years, months, days, hours, minutes, and seconds), perform accurate math on date-times, handle time zones and Daylight Savings Time. lubridate has a consistent, memorable syntax that makes working with dates less frustrating.

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

Hiya, maybe there is a native R function for this and if so please let me know! I have 2 data.frames with start and end dates, they read in as strings and I am converting to POSIXct. How can I check for overlap? The end result ideally will be a single data.frame containing all the columns of the other two with rows where there were date overlaps.

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 >

> 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

Please find below the package announcement for the R package lubridate available from cran. Thank you, Garrett Grolemund Rice University ##lubridate Date-time data can be frustrating to work with in R. R commands for date-times are generally unintuitive and change depending on the type of date-time object being used. Moreover, the methods we use with date-times must be robust to time zones,

Please find below the package announcement for the R package lubridate available from cran. Thank you, Garrett Grolemund Rice University ##lubridate Date-time data can be frustrating to work with in R. R commands for date-times are generally unintuitive and change depending on the type of date-time object being used. Moreover, the methods we use with date-times must be robust to time zones,

With newest R devel #sessionInfo() R Under development (unstable) (2012-01-10 r58085) Platform: amd64-portbld-freebsd10.0 (64-bit) locale: [1] de_DE.ISO8859-15/de_DE.ISO8859-15/de_DE.ISO8859-15/C/de_DE.ISO8859-15/de_DE.ISO8859-15 attached base packages: [1] stats graphics grDevices utils datasets methods base I get the following error when I try to build and install lubridate from

Full_Name: Suharto Anggono Version: 2.8.1 OS: Windows Submission from: (NULL) (125.165.84.118) PR#14076 inspired me to write this. > t1 <- as.POSIXct("1970-01-01 00:00:00", tz="GMT") > t2 <- as.POSIXlt("1970-01-01 00:00:00", tz="GMT") > t1 - t2 Time difference of 7 hours Above, t1 and t2 represent the same time in the same specified

Version 2.2 of the lubridate package is now available. lubridate makes it easier to work with date-time data. For example, it provides: * simple functions to extract and modify components of a date-time, such as years, months, days, hours, minutes, and seconds: year(), month(), day(), ... * quick and easy functions to parse date-times: ymd(), dmy(), mdy(), ... * helper functions for handling

Version 2.2 of the lubridate package is now available. lubridate makes it easier to work with date-time data. For example, it provides: * simple functions to extract and modify components of a date-time, such as years, months, days, hours, minutes, and seconds: year(), month(), day(), ... * quick and easy functions to parse date-times: ymd(), dmy(), mdy(), ... * helper functions for handling

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]

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

I took a look at Hadley's lubridate which seems a very neat package, but i am having a small problem with  concatenating lubridates to build vectors of it. Namely when function c( )  is applied to lubridate seems to change time to a local timezone in this particular case changing the date to previous one.  > d<-ymd('20111231') > d [1] "2011-12-31 UTC" > c(d) [1]

Apologies for the intrusion. I am a lurker on list. I have been working to convert a digitized signal from a matlab file into R for analysis and other applications. R.matlab is working fine, and it is easy to convert the matlab date-time number (days since year 0) into R date-time numbers (seconds since 1970-01-01). Unfortunately, when I cast the R date-time number into POSIXct format it seems

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 =

Hello, Suppose we need a function that takes a POSIXct object and need to calculate the time difference between it and GMT time: gmtDiff <- function(time) { time.gmt <- as.POSIXct(format(time, tz="GMT")) time.plt <- as.POSIXlt(time) dlstime <- ifelse(time.plt$isdst > 0, 1, 0) timezone <- as.numeric(difftime(time, time.gmt, units="hours"))