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.