tz_used columns based on either the first timezone specified into the tibble or
a user supplied timezone. This function is meant to used in a pipe with the
realtime_add_local_datetime(.data, set_tz = NULL)
Tibble created by
A timezone string in the format of
Date from realtime_dd is supplied in UTC which is the easiest format to work with across timezones.
realtime_add_local_datetime adjusts local_datetime to a common timezone. This is most useful when all stations exist
within the same timezone though it is possible.