When was Japan named after the meaning "land of the rising sun"?

Question

Was it long before the advent of writing? And was that "rising sun" really Helios (i.e. today's Sun) or Uranus (for Uranus could have been the first Sun, prior to Saturn and Jupiter, according to its chemical constitution similar to that of our present sun)?

Answer 1

What? Uranus a sun? What in the heck are you reading?

The gas giants are planets. Jupiter is closest to being a star from having enough mass to initiate fusion, but it does NOT have enough mass to do so. The other giants are less massive and not near enough to become stars.

The chinese characters already existed when it was named:

Both Nippon and Nihon literally mean "the sun's origin", that is, where the sun originates, and are often translated as the "Land of the Rising Sun". This nomenclature comes from imperial correspondence with Sui Dynasty and refers to Japan's eastward position relative to China. Before Japan had relations with China, it was known as Yamato and Hi-no-moto, which means "source of the sun"
http://www.answers.com/topic/names-of-japan

Answer 2

The kanji characters that make up Japan's name mean "sun-origin", which is why Japan is sometimes identified as the "Land of the Rising Sun". Therefore it was after the development of Kanji script in the 5th and 6th century.