Tenson Kigen (天孫紀元)

Tenson kigen is a Japanese year-reckoning system which sets the year of tenson korin (the descent to earth of the grandson of the sun goddess) as its first year. Although it hardly has any chance to be used today, it doesn't mean it is never used.

This year (2009, the 2,669th year of the Imperial reign) is the 1,795,142th year of tenson kigen.