On 2009 May 1, at 04:22 , Palmen, KEV (Karl) wrote:
Two 353-year cycles is not too bad. I didn't find out about it for some time and have it listed in
http://www.the-light.com/cal/Lunisolar_333.html
It has 257861 days and is formed by combining the primary cycles of 315 and 391 years.
Its mean year is 365.24221 days and mean month is 29.53057719 days.
Irv replies: I discounted the 706-year cycle because its mean year = 365d 5h 48m 47s (close to the so-called mean tropical year) and mean month = 29d 12h 44m 1.87s are both too short.
My targets were intentionally slightly shorter than the mean northward equinoctial year and slightly shorter than the mean synodic month.
On the other hand, 9 x 353 = 3177 years has has a mean year = 365d 5h 49m 1s and mean month = 29d 12h 44m 2.97, which are both too long.
Odd-numbered higher multiples (x11, x13, x15, x17...) make the mean year and mean month progressively shorter.
The x11 multiple is closer to the present-era targets (365d 5h 48m 58s and 29d 12h 44m 2.77s) but I prefer intentionally slightly short mean year and month because both the mean northward equinoctial year and the mean synodic month are getting progressively shorter.
-- Irv Bromberg, Toronto, Canada
