NTP

Synchronize device time with a remote server

POSIX TZ variable, defaults to UTC0 aka "Coordinated Universal Time". For example, basic offset is expressed as either UTC2 (meaning "UTC minus 2 hours"), or UTC-2 ("UTC plus 2 hours"). For the list of possible values based on IANA Time Zone Database, see our wiki entry. For the technical documentation and more complicated examples, see libc tzset(3) manual page