badrubbish

One of my hobbies is constructing lunar and lunisolar calendars. Without getting into too much detail, I'd like to pin the current one to a recurring cycle that begins on the first new moon after an equinox. I want this calendar to have begun counting fron a date a few centuries ago, which means historical new moon events will influence when the current cycle began. So, TLDR, I need to know when the new moon was in a particular month in the 1120s.

Six millennium catalog of phases of the moon
Easier to navigate, only goes back to 1900

I'm happy to just go with the most common date for the equinox, but precision there would be lovely as well...

Solstices & equinoxes 1100-1149

I'm glad I checked, because it looks like the most typical dates have shifted substantially in the last few hundred years.

In case I want to account for saros cycles, planetary appearances, or etc:

NASA's page on eclipses
eclipsewise.com
Very rough synodic & sidereal orbit periods of the planets
Planet brightness, distance, size for laypeople
Pluto, not listed (😭), is never visible without a telescope.
About Venus (583.92 days between recurrences)
About Jupiter (398.88)
About Mercury (115.88)
About Saturn (378.09)
About Mars (119.94 days between recurrences)
Seasonal constellations (this calendar's reference point is below 40N)

Some numbers (units are days unless otherwise stated):
Sidereal month, 27.321
Synodic month, 29.530587981 (roughly 29.53059)
Tropical month, 27.321582
Anomalistic month, 27.554551
Draconic month, 27.212220
Sidereal year, 365.256363004
Tropical year, 365.2422
Saros, 6585.3211
Triple saros or exeligmos, 19755.9633

Just for luck:

Time and date calculator

And that's all for now.

Entries tagged with calendars

Calendar-making reference post

Profile

March 2019

Syndicate

Most Popular Tags

Page Summary

Style Credit

Expand Cut Tags