settz - Set system time zone information.
The settz command sets the system time zone information, based on the current zoneinfo database configuration. If the zoneinfo database is not configured, it sets the system time information as if the zoneinfo database were configured to default to Coordinated Universal Time (UTC).
Specifically, it calls tzset() to get current default time zone information, ignoring the TZ environment variable, if set, creates a struct timezone with time zone offset, and daylight savings information, then calls settimeofday(). The current system date and time are not changed.
This command is always run the system is entering a multiuser run level and should be run whenever default time zone information has been changed by the zic command.
You must have superuser privileges to use this command.
Commands: timezone(3), tzset(3), timezone(8), zic(8) delim off