Today is Leefo 1st, the first day in the D’ni Calendar!
From the Guild of Archivists website:
The Ronay became aware that their planet would eventually be destroyed by their sun as it transformed into a red giant star. Upon this realization, they evacuated the majority of their population to a new Age, Terahnee. Some religious sects and splinter groups took advantage of the evacuation to strike out on their own, separating themselves from the rest of their civilization. One such group was the D’ni, led by Ri’neref, who received permission from the Ronay King to break away from the Ronay people during the exodus.
As had always been the case with the Ronay, a group of surveyors was sent to D’ni, before the group officially moved there, to establish the Great Zero and the line emanating from it. A monument was built on the Great Zero in the year 0 DE [7657 BC].