User blog:Jrp04f/Doesn't this show take place during the '60s?

If I understand the back story on this series correctly, the calendar generally used has Year 0 about fifty years earlier than on the Gregorian calendar used in the real world, meaning that this show takes place during the mid-1960s. Therefore, why is there modern technology -- cellphones, the Internet, etc -- let alone giant robots and anti-gravity airships?