similar to: POSIXlt and trunc

Technically, there is a round() for 'Date' objects, but it doesn't seem very useful, because it basically just fall back to the default round() method, which only takes the 'digits' argument. Here's an example: > date <- Sys.Date() > class(date) [1] "Date" We see that there are only two round() methods in addition to the implicit built-in one; >

?s 14:36 de 08/02/2024, Olivier Benz via R-devel escreveu: >> On 8 Feb 2024, at 15:15, Martin Maechler <maechler at stat.math.ethz.ch> wrote: >> >>>>>>> Ji?? Moravec >>>>>>> on Wed, 7 Feb 2024 10:23:15 +1300 writes: >> >>> This is my first time working with dates, so if the answer is "Duh, work >>> with

I have found what looks like a small problem in trunc.POSIXt() involving the transition to/from standard time and daylight savings time. Assuming my assessment is correct, I have a potential solution to offer. If a time in daylight savings time is rounded such that the rounded value is on the other side of the transition, the isdst element does not get changed accordingly. I have tested only

This is a workaround, and could be the basis for a round.Date improvement: date <- Sys.Date() as.Date(round(as.POSIXct(date), "years")) as.Date(round(as.POSIXct(Sys.Date() + 180), "years")) Duncan Murdoch On 08/02/2024 12:23 p.m., Henrik Bengtsson wrote: > Technically, there is a round() for 'Date' objects, but it doesn't > seem very useful,

The following code: cut(as.POSIXct("2009-11-01 04:00:00", tz="America/Los_Angeles"), "1 day") gives the error: Error in seq.int(0, to - from, by) : 'to' must be finite This is related to November 1st, 2009 being the switchover date from daylight savings time to standard time in the America/Los_Angeles time zone. In particular, in cut.POSIXt, the starting

>>>>> Ji?? Moravec >>>>> on Wed, 7 Feb 2024 10:23:15 +1300 writes: > This is my first time working with dates, so if the answer is "Duh, work > with POSIXt", please ignore it. > Why is not `round.Date` and `trunc.Date` "implemented" for `Date`? > Is this because `Date` is (mostly) a virtual class setup for a

> On 8 Feb 2024, at 15:15, Martin Maechler <maechler at stat.math.ethz.ch> wrote: > >>>>>> Ji?? Moravec >>>>>> on Wed, 7 Feb 2024 10:23:15 +1300 writes: > >> This is my first time working with dates, so if the answer is "Duh, work >> with POSIXt", please ignore it. > >> Why is not `round.Date` and

How can I extract only the time component from an POSIXlt object? For example if I try the following it still returns both the date and time... >as.POSIXlt(tr.date[1]) [1] "2010-10-18 21:46:53" >as.POSIXlt(tr.date[1],"%H:%M:%S") [1] "2010-10-18 21:46:53" round and trunc don't help... is there an "as.Time" equivalent to as.Date ? Thanks,

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]

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

This is my first time working with dates, so if the answer is "Duh, work with POSIXt", please ignore it. Why is not `round.Date` and `trunc.Date` "implemented" for `Date`? Is this because `Date` is (mostly) a virtual class setup for a better inheritance or is that something that is just missing? (like `sort.data.frame`). Would R core welcome a patch? I decided to convert

Arrays of POSIXlt dates always return a length of 9. This is correct (they're really lists of vectors of seconds, hours, and so forth), but other methods disguise them as flat vectors, giving superficially surprising behaviour: strings <- paste('2009-1-', 1:31, sep='') dates <- strptime(strings, format="%Y-%m-%d") print(dates) # [1]

Dear Listers, I have encountered a strange problem using diff() and POSIXt: dts<-c("15/4/2003","15/7/2003","15/10/2003","15/04/2004","15/07/2004","15/10/2004","15/4/2005","15/07/2005","15/10/2005","15/4/2006") dts <- strptime(dts, "%d/%m/%Y") class(dts) [1] "POSIXt"

Dear Listers, I have encountered a strange problem using diff() and POSIXt: dts<-c("15/4/2003","15/7/2003","15/10/2003","15/04/2004","15/07/2004","15/10/2004","15/4/2005","15/07/2005","15/10/2005","15/4/2006") dts <- strptime(dts, "%d/%m/%Y") class(dts) [1] "POSIXt"

Hi, I have two data sources. One records time in PST time zone, the other in GMT. I want to compute the difference between the two, but don't see how. Here is an example where I compute time difference between identical times each (meant to be) relative to its time zone. > as.POSIXlt("2000-05-10 10:15:00", "PST") - as.POSIXlt("2000-05-10 10:15:00",

Hi. This feels like a bug to me, or at least an undocumented feature, but I thought I'd see what people here thought of it. Consider a POSIXlt object like this one: > a <- as.POSIXlt ("2011-01-23 12:45:45") > class (a) [1] "POSIXlt" "POSIXt" Fine. Now, if I do some arithmetic on that object, the result is converted to POSIXct. > class (a

I'm trying to rbind two data frames, both with the same columns names. One of the columns is a variable with date-time and this variable is causing the rbind to fail--giving the error "Error in names(value[[jj]])[ri] <- nm : 'names' attribute [7568] must be the same length as the vector [9]" Is there a way to stack or rbind these two data frames even with this extended

Dear all, I hope this is a right place to post this; r-help might be appropriate but it looks like I'm suggesting a change in base package, so I decided to post here. (+ Apologies if that has been changed recently -- the version I'm using is R.2.12.2 on Windows.) I've noticed an unexpected behavior of trunc.POSIXt: foo <- seq(as.POSIXct( "2009-10-23 22:00:00"),

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:

[R 1.6.1] PROBLEM If text() is called with an argument of type POSIXlt, I get the following error message: "Error in as.double.default(x) : (list) object cannot be coerced to vector type 14" REMARK plot() accepts this data. EXAMPLE data( Lifeboats, package='vcd' ) attach(Lifeboats) plot( launch, total ) text( launch, total,