Sam Albers
2018-Jun-28 17:58 UTC
[R] Unable to return gmtoff from as.POSIXlt without converting date string to as.POSIXct first
Is it possible for someone to explain what is going on here? I would expect that `as.POSIXlt` would be able to accept `datestring` and return all the elements without having to convert it using `as.POSIXct` first. Do `as.POSIXlt` and `as.POSIXct` do different things with the `tz` arg? datestring <- "2017-01-01 12:00:00" foo <- as.POSIXlt(datestring, tz = "America/Moncton") foo [1] "2017-01-01 12:00:00 AST" foo$gmtoff [1] NA bar <- as.POSIXlt(as.POSIXct(datestring, tz = "America/Moncton")) bar [1] "2017-01-01 12:00:00 AST" bar$gmtoff [1] -14400 Thanks in advance, Sam [[alternative HTML version deleted]]
Jeff Newmiller
2018-Jun-28 22:16 UTC
[R] Unable to return gmtoff from as.POSIXlt without converting date string to as.POSIXct first
Read ?DateTimeClasses regarding gmtoff. In short, it is implementation-dependent. On June 28, 2018 10:58:13 AM PDT, Sam Albers <tonightsthenight at gmail.com> wrote:>Is it possible for someone to explain what is going on here? I would >expect >that `as.POSIXlt` would be able to accept `datestring` and return all >the >elements without having to convert it using `as.POSIXct` first. Do >`as.POSIXlt` and `as.POSIXct` do different things with the `tz` arg? > >datestring <- "2017-01-01 12:00:00" >foo <- as.POSIXlt(datestring, tz = "America/Moncton") >foo >[1] "2017-01-01 12:00:00 AST" >foo$gmtoff >[1] NA > >bar <- as.POSIXlt(as.POSIXct(datestring, tz = "America/Moncton")) >bar >[1] "2017-01-01 12:00:00 AST" >bar$gmtoff >[1] -14400 > >Thanks in advance, > >Sam > > [[alternative HTML version deleted]] > >______________________________________________ >R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide >http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code.-- Sent from my phone. Please excuse my brevity.