is entirely in UTC (Universal Time, Coordinated), Timezones and DST (Daylight Saving Time) are applied locally by the system. The file
is a copy of, or symlink to, a zone information file from
. The RTC may be in localtime or in UTC, as specified by the 3rd line of
, which will be one of LOCAL or UTC to indicate how the RTC clock has been set. Users can easily change this setting using the checkbox System Clock Uses UTC
in the Date and Time
graphical configuration tool. See Chapter 3, Configuring the Date and Time
for information on how to use that tool. Running the RTC in UTC is recommended to avoid various problems when daylight saving time is changed.