How do you change the timezone of Sys.time()

Question

I am in the PDT timezone and I want to change the variable "s" to the GMT timezone. Any idea how?

s<-Sys.time()
s
as.POSIXct(s,"GMT")

OUTPUT

> s<-Sys.time()
> s
[1] "2015-06-17 17:56:17 PDT"
> as.POSIXct(s,"GMT")
[1] "2015-06-17 17:56:17 PDT" # <--  how do I get this in GMT??

Termor

Sys.setenv(TZ="GMT") – Parrie

@Parrie This will work but maybe he doesn't want to change his system timezone. – Nuncio

Do you want the corresponding time in GMT for the PDT time, or do you want to just essentially change the label from PDT to GMT? – Kazantzakis

I don't want to just change the label. I want to change the actual time. So if the time is 17:56:17 PDT i want to add/subtract to get to a differnent timezone. – Termor

Answer 1

Depending on what you want to do exactly, there are a couple of options:

s <- Sys.time()
s
#[1] "2015-06-18 11:21:22 EST"

Transfer from local time to GMT, without adustment:

as.POSIXct(format(s),tz="GMT")
#[1] "2015-06-18 11:21:22 GMT"

Transfer to GMT, adjusting for the time difference between local time and GMT.

`attr<-`(s,"tzone","GMT")
#[1] "2015-06-18 01:21:22 GMT"

, which is equivalent to the assignment operation:

attr(s,"tzone") <- "GMT"

Kazantzakis

Answer 2

You can also use .POSIXct:

s <- .POSIXct(s, "GMT")

Heterograft

Just noting that this adjusts the time to GMT (i.e. - equivalent to second example in my answer)> – Kazantzakis

Answer 3

You could use clock::date_now(zone = "GMT").

Kugler