change_tz {ds4psy}

Change time zone (without changing represented time).

Description

change_tz changes the nominal time zone (i.e., the time display) without changing the actual time.

Usage

change_tz(time, tz = "")

Arguments

time

Time (as a scalar or vector). If time is not a calendar time (of the "POSIXct" class) the function first tries coercing time into "POSIXct" without changing the denoted time.

tz

Time zone (as character string). Default: tz = "" (i.e., current system time zone, Sys.timezone()). See OlsonNames() for valid options.

Details

change_tz expects inputs to time to be calendar time(s) (of the "POSIXct" class) and a valid time zone argument tz (as a string) and returns the same time(s) as local time(s) (of the "POSIXlt" class).

Value

A local time of class "POSIXlt".

See Also

change_time function which preserves time display but changes time; Sys.time() function of base R.

Other date and time functions: change_time(), cur_date(), cur_time(), days_in_month(), diff_dates(), diff_times(), diff_tz(), is_leap_year(), what_date(), what_month(), what_time(), what_wday(), what_week(), what_year(), zodiac()

Examples

change_tz(Sys.time(), tz = "Pacific/Auckland")
change_tz(Sys.time(), tz = "Pacific/Honolulu")

# from "POSIXct" time:
tc <- as.POSIXct("2020-07-01 12:00:00", tz = "UTC")
change_tz(tc, "Australia/Melbourne")
change_tz(tc, "Europe/Berlin")
change_tz(tc, "America/Los_Angeles")

# from "POSIXlt" time:
tl <- as.POSIXlt("2020-07-01 12:00:00", tz = "UTC")
change_tz(tl, "Australia/Melbourne")
change_tz(tl, "Europe/Berlin")
change_tz(tl, "America/Los_Angeles")

# from "Date":
dt <- as.Date("2020-12-31")
change_tz(dt, "Pacific/Auckland")
change_tz(dt, "Pacific/Honolulu")  # Note different date!

# with a vector of "POSIXct" times:
t2 <- as.POSIXct("2020-12-31 23:59:55", tz = "America/Los_Angeles")
tv <- c(tc, t2)
tv  # Note: Both times in tz of tc
change_tz(tv, "America/Los_Angeles")