Get/set time zone component of a date-time.
Date-time must be a POSIXct, POSIXlt, Date, chron, yearmon, yearqtr, zoo, zooreg, timeDate, xts, its, ti, jul, timeSeries, and fts objects.
- a date-time object
Setting tz does not update a date-time to display the
same moment as measured at a different time zone. See
with_tz. Setting a new time zone creates a
new date-time. The numerical value of the hours element
stays the same, only the time zone attribute is replaced.
This creates a new date-time that occurs an integer value
of hours before or after the original date-time.
If x is of a class that displays all date-times in the GMT timezone, such as chron, then R will update the number in the hours element to display the new date-time in the GMT timezone.
For a description of the time zone attribute, see
- the first element of x's tzone attribute vector as a character string. If no tzone attribute exists, tz returns "GMT".
x <- now() tz(x) tz(x) <- "GMT" x tz(x) <- "America/New_York" x Sys.setenv(TZ = "GMT") now() tz(now()) Sys.unsetenv("TZ")