At this point you’ve read in all of the files that make up a minimal
Debian system, but you must perform some configuration before the
system will run.
You’ll be asked to select your time zone. There are many ways to
specify your time zone; we suggest you go to the “Directories:” pane
and select your country (or continent). That will change the
available time zones, so go ahead and select your geographic
locality (i.e., country, province, state, or city) in the
“Timezones:” pane.
Next, you’ll be asked if your system clock is to be set to GMT or
local time. Select GMT (i.e., “Yes”) if you will only be running
Linux on your computer; select local time (i.e., “No”) if you will
be running another operating system as well as Debian. Unix (and
Linux is no exception) generally keeps GMT time on the system clock
and converts visible time to the local time zone. This allows the
system to keep track of daylight savings time and leap years, and
even allows a user who is logged in from another time zone to
individually set the time zone used on his or her terminal.