Date-time must be a POSIXct, POSIXlt, Date, chron,
yearmon, yearqtr, zoo, zooreg, timeDate, xts, its, ti,
jul, timeSeries, and fts objects. 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
DateTimeClasses
.