date-zone {clock} | R Documentation |
date_zone()
gets the time zone.
date_set_zone()
sets the time zone. This retains the underlying
duration, but changes the printed time depending on the zone that is
chosen.
date_zone(x) date_set_zone(x, zone)
x |
A date-time vector. |
zone |
A valid time zone to switch to. |
This function is only valid for date-times, as clock treats R's Date class as a naive type, which always has a yet-to-be-specified time zone.
date_zone()
returns a string containing the time zone.
date_set_zone()
returns x
with an altered printed time. The
underlying duration is not changed.
library(magrittr) # Cannot set or get the zone of Date. # clock assumes that Dates are naive types, like naive-time. x <- as.Date("2019-01-01") try(date_zone(x)) try(date_set_zone(x, "America/New_York")) x <- as.POSIXct("2019-01-02 01:30:00", tz = "America/New_York") x date_zone(x) # If it is 1:30am in New York, what time is it in Los Angeles? # Same underlying duration, new printed time date_set_zone(x, "America/Los_Angeles") # If you want to retain the printed time, but change the underlying duration, # convert to a naive-time to drop the time zone, then convert back to a # date-time. Be aware that this requires that you handle daylight saving time # irregularities with the `nonexistent` and `ambiguous` arguments to # `as.POSIXct()`! x %>% as_naive_time() %>% as.POSIXct("America/Los_Angeles") y <- as.POSIXct("2021-03-28 03:30:00", "America/New_York") y y_nt <- as_naive_time(y) y_nt # Helsinki had a daylight saving time gap where they jumped from # 02:59:59 -> 04:00:00 try(as.POSIXct(y_nt, "Europe/Helsinki")) as.POSIXct(y_nt, "Europe/Helsinki", nonexistent = "roll-forward") as.POSIXct(y_nt, "Europe/Helsinki", nonexistent = "roll-backward")