I just bought an iMac DV and after the Setup Assistant finished registering me with Apple, my keyboard, and date and time settings are all set for the United States. Do I have to manually configure these settings?

Yes. While the operating system on your computer may be in your language, some of the computers settings may need to be made manually. To set the proper keyboard, open the Keyboard control panel. To set the date and time to your preference, open the Date & Time control panel.