Is this based upon the biblical length of a year ? The Heptad ?
I am still trying to find references that the year used to be less than 365 days.
I found the following:
"Sir Isaac Newton stated, "All nations, before the just length of the solar year was known, reckoned months by the course of the moon, and years by the return of winter and summer, spring and autumn; and in making calendars for their festivals, they reckoned thirty days to a lunar month, and twelve lunar months to a years, taking the nearest round numbers, whence came the division of the ecliptic into 360 degrees." ( Anderson, Robert. The Coming Prince. London: Hodder & Stroughton, 1894. ) "
But that is just talking about an approximation to the year. Not a reference that the year actually lasted 360 days.
Same at http://www.xs4all.nl/~rkeulen/watch/metric.html
Shorter days in the past:
http://www.gi.alaska.edu/ScienceForum/ASF7/742.html