force_tz
returns the date-time that has the same clock time as input time,
but in the new time zone. force_tzs
is the parallel version of force_tz
,
meaning that every element from time
argument is matched with the
corresponding time zone in tzones
argument.
force_tz(time, tzone = "", roll = FALSE)
force_tzs(time, tzones, tzone_out = "UTC", roll = FALSE)
a POSIXct, POSIXlt, Date, chron date-time object, or a data.frame
object. When a data.frame all POSIXt elements of a data.frame are processed
with force_tz()
and new data.frame is returned.
a character string containing the time zone to convert to. R must recognize the name contained in the string as a time zone on your system.
logical. If TRUE, and time
falls into the DST-break, assume
the next valid civil time, otherwise return NA. See examples.
character vector of timezones to be "enforced" on time
time
stamps. If time
and tzones
lengths differ, the smaller one is recycled
in accordance with usual R conventions.
timezone of the returned date-time vector (for force_tzs
).
a POSIXct object in the updated time zone
Although the new date-time has the same clock time (e.g. the same values in the year, month, days, etc. elements) it is a different moment of time than the input date-time.
As R date-time vectors cannot hold elements with non-uniform time zones,
force_tzs
returns a vector with time zone tzone_out
, UTC by default.
x <- ymd_hms("2009-08-07 00:00:01", tz = "America/New_York")
force_tz(x, "UTC")
#> [1] "2009-08-07 00:00:01 UTC"
force_tz(x, "Europe/Amsterdam")
#> [1] "2009-08-07 00:00:01 CEST"
## DST skip:
y <- ymd_hms("2010-03-14 02:05:05 UTC")
force_tz(y, "America/New_York", roll=FALSE)
#> [1] NA
force_tz(y, "America/New_York", roll=TRUE)
#> [1] "2010-03-14 03:00:00 EDT"
## Heterogeneous time-zones:
x <- ymd_hms(c("2009-08-07 00:00:01", "2009-08-07 01:02:03"))
force_tzs(x, tzones = c("America/New_York", "Europe/Amsterdam"))
#> [1] "2009-08-07 04:00:01 UTC" "2009-08-06 23:02:03 UTC"
force_tzs(x, tzones = c("America/New_York", "Europe/Amsterdam"), tzone_out = "America/New_York")
#> [1] "2009-08-07 00:00:01 EDT" "2009-08-06 19:02:03 EDT"
x <- ymd_hms("2009-08-07 00:00:01")
force_tzs(x, tzones = c("America/New_York", "Europe/Amsterdam"))
#> [1] "2009-08-07 04:00:01 UTC" "2009-08-06 22:00:01 UTC"