From: "Peter Clark" <peter-clark@...>:

> On Monday 13 May 2002 16:37, Danny Wier wrote:

> > The Elven calendar is both lunar and solar, based on a cycle of 21 solar
> > years and alternating lunar months of 30 and 29 days. Within the 21 year
> > cycle, the 1st, 3rd, 6th, 8th, 11th, 14th, 16th, 19th and 21st years of
the
> > cycle are 13-month years ("long years"), or 383 or 384 days. The other
> > years are 12-month years ("short years") and are 354 days long, just
like
> > the Islamic year. The first month of each year can be either 29 or 30
days
> > depending on the year.

>         How man years are "abundant" (384 days)? Running this through my
handy
> home-brew python lunar-solar calendar test program reveals that the
closest
> "ideal" would be either three or four abundant years. UNFORTUNATELY, this
> scheme will very quickly derail itself. Consider:
>
>         After 21 years, with 9 long years (three of which are abundant),
the seasons
> would be off by 36.9 days, and the moon would be off by -0.48 days. That
> means that after two cycles, or 42 years, the seasons would be off by more
> than two months, and the moon would be off by an entire day.
>         After 21 years, with 9 long years (four of which are abundant),
the seasons
> would be off by 37.9 days, and the moon would be off by 0.52 days. Pretty
> much the same results. Is there something else that manages to keep the
moon
> and seasons in line?

I forgot to determine which years would be 384 days long; they would be the
1st, 6th, 11th, 16th and 21st months in one 21 year cycle, and 3rd, 8th,
11th and 16th in the next. So I would need a 42-year cycle then.

The "official" beginning of a season (that is, a quadrimester based on the
solstices and equinoxes) is the first of the month after the solstice or
equinox in question.

But since climactic seasons vary from location to location, seasons aren't
really that universal; many Techians recognize trimestral seasons: the rainy
season (spring), the hot and dry season (summer), and the cool or cold
season (fall-winter).

By the way, the average (physical of course) lifespan of an elf is about
four of these complete cycles, or 168 years.

~Danny~