A month approximates the moon's synodic orbital period. A common month comprises 30 days (if it is odd-indexed), or 29 days (if it is even-indexed). Every so often, a leap month is inserted, which may have 30 or 31 days. There are twelve months in a common year, and thirteen in a leap year.
If the cycle number (which is the year number mod 334, explained later) mod 19 mod 3 is 0, then the year is a common year. Otherwise, it is a leap year.
The leap month is inserted at the end of a leap year. The number of leap months passed in the current cycle is recorded. If this number mod 17 is even, then the leap month has 31 days, otherwise if it is odd, it has 30 days.
A year may contain 12 or 13 months, and total 354, 384, or 385 days.
A year approximates Earth's tropical orbital period.
A cycle comprises 334 years. The length of the cycle was chosen because the number of lunar synodic months in 334 tropical years is quite nearly a whole number, simplifying calculations. An epicycle comprises 77 cycles (and is thus 25,718 MLSC years or about 25,717 Julian years). The current cycle in the epicycle determines the age. An epicycle approximates Earth's axial precession, and thus what constellation the vernal equinox lies in. Ages vary in length from 6 to 7 cycles, with Pisces, Sagittarius, Virgo, Leo, and Taurus having 7, and the rest 6.
| Age | Length (cycles) | Start (Gregorian) |
|---|---|---|
| Aries | 6 | 990 BCE |
| Pisces | 7 | 1013 CE |
| Aquarius | 6 | 3351 CE |
| Capricornus | 6 | 5355 CE |
| Sagittarius | 7 | - |
| Ophiuchus | 6 | |
| Libra | 6 | |
| Virgo | 7 | |
| Leo | 7 | |
| Cancer | 6 | |
| Gemini | 6 | 5332 BCE |
| Taurus | 7 | 3328 BCE |
The age determines the name of the starting month. It's cosmetic, and does not affect any ordinal numbers.
Epicycles start with Aries and proceed backwards around the zodiac. The current Age of Pisces began year -1002 (March 20th, 1013 CE), and will end 1670 (March 20th, 3351 CE).
The largest division of time is the gal. A gal is 8,750 epicycles (and is thus 225,032,500 MLSC years or about 225,027,888 Julian years). A gal approximates the time taken for the sun to orbit the milky way once (the galactic year). The current epicycle's beginning of the age of Aries defines the start of gal 0. The solar system therefore formed in gal -20, and the universe in gal -61.
| Unit | Length |
|---|---|
| Day | 86,400 s |
| Month | 29-31 d |
| Year | 12-13 mo 354-385 d |
| Cycle | 334 yr 4,131 mo 121,991 d |
| Age | 6-7 Cycles 2,004-2,338 yr |
| Epicycle | 12 Ages 77 cycles 25,718 yr |
| Gal | 8,750 epicycles 225.0325 Myr |
The following information is not necessary to understand the calendar, but instead gives enhanced vocabulary to describe it.
The kalends are the first day of the month (roughly a new moon). The nones are the eighth day of the month (roughly a first quarter moon). The ides are the sixteenth day of the month (roughly a full moon). The icas is the twenty-third day of the month (roughly a third quarter moon). The terms kalends, nones, and ides are pluralia tantum, but icas is a normal countable noun.
The days following one of these dates are given the following names:
| Days after | Name | Kal. | Non. | Eid. | Ica. |
|---|---|---|---|---|---|
| 0 | - | 1st | 8th | 16th | 23rd |
| 1 | Sol’s Day | 2nd | 9th | 17th | 24th |
| 2 | Luna’s Day | 3rd | 10th | 18th | 25th |
| 3 | Mars’s Day | 4th | 12th | 19th | 26th |
| 4 | Mercury’s Day | 5th | 13th | 20th | 27th |
| 5 | Jupiter’s Day | 6th | 13th | 21st | 28th |
| 6 | Venus’s Day | 7th | 14th | 22nd | 29th |
| 7 | Saturn’s Day | - | 15th | - | 30th |
| 8 | Uranus’s Day | - | - | - | 31st |
These could be treated as weekdays, if one wished. The length of a "week" would then be from 7-9 days: 7-8-7 followed by a week 7-9 days long. Note that Uranus’s day can only occur at the end of a long leap month, so it happens only once about every four years. Saturn’s day only occurs on the 15th and 30th.
Convenient side effects of this calendar include: