To Keep the Time - The Athalassan lunisolar Calendar

Origins

It is a belief deeply rooted in Athalã culture that the Gods can not rule the world symultaneously. Instead, each of the six gods comes into power - or as they say, "holds the staff of the world" - in accordance to the six cycles that the white moon does around the world in a solar year.

There was a time, the priests say, when the gods ruled as a exarch, but being unable to agree, their rule often resulted in disastrous civil wars that destroyed the world with earthquakes, floods and endless storms. Feeling compassion towards mankind, they decided to split their powers, creating the moons to establish how long each god would to rule - this myth shows how deeply entrenched the values of monarchy are in the Athalã's worldview.

The Traditional Lunar Calendar

Before the rule of the Great Thàm Gantaïssàn Bharaïnanã, the fifth king of the pre-imperial dynasty, the Athalã kept their time exclusively following the white-moon. The existance of a solar year was known of course, and the lenghtening and shortening of the days with the seasons had long been a noticeable feature for "skykeepers", but only the moon was considered important timekeeping devices. The red-moon was completely ignored as well.

The six seasons of the year were lasted as long as the six white moons and bore the gods' names.

The solar year canonically begun at middle of the Month of Storms (Eïtã, named after Eït, the god of storms, winter, stars and premonition), but the year officially started with the new moon of Thamoïn, the father god of the Athalã pantheon, thirty days later than that. The season called Thamoïnã or Month of Waters, corresponding to our february and march, is the period when the melting of the snow caps on the sacred mound causes the flooding of the rivers.

Sixty days later, as the moon renews once again, it's the turn of Herî, the mother goddess, to hold the staff. Her season, the Month of Blooms or Herinã, starts with the blooming of magnolias, her sacred flower, and corresponds to april-may.

It's followed by Alphèrã, The Month of War (june-july) and Adamosã, the Month of Harvest (august-september). The migration of the wandering birds kicks off the Month of Travellers, Hentã (october-november) ending with the Month of Storms.

Issues with the Traditional System

Unfortunately, the calendar devised by the Ancient Athalã didn't quite work. It wasn't long before the sky keepers noticed that it took only ten years for the white-moon to shift its cycle forward by four days. By following the lunar calendar, it took roughly one hundred and fifty years for the seasons two shift by sixty days - a complete lunar cycle. As the rule of gods corresponded to seasonal festival and occurrences such change was quite noticeable.

Ocasionally, when such shift occurred, the priests arbitrarily announced that a season ought to be skipped or shortened, or that two gods ought to share one particular moon. These decisions were made on a local level, however, and the result was the presence of hundreds of different villages worshipping different gods at the same time - something that goes against Athalassan beliefs of godly universal order.

This is also one of the reason why, for how meticulous and exhaustive pre-imperial records had been, they can be hard to date precisely and univocally.

The Solution - Thàm Gantaïssàn's Lunisolar Calendar

Thàm Gantaïssàn II of the pre-imperial Bharaïnanã dynasty was the one to solve the issue, creating a univocal timekeeping system for the kingdom. He followed his the path of his uncle and predecessor, the inventor of Athalassã's measuring system and a promotor of the spread of Geometry as a clarifying, dispute-solving science, in his desire to uniform knowledge and administration across his lands.

The system devised by the King, or, more likely, the scribes under his command, was very different from the traditional one.

It kept the red-moon and the solar year as reference points instead of the shifting white-moon.

The lunisolar year begun thirty days after the winter solstice, following the traditional calendar, but there were now nine forty-day months (instead of six sixty-day ones), reflecting the lunation of the red-moon and fitting perfectly inside the 360 days long year. The red-moon, however, much like the white-moon shifted noticeably during the year: on the same day, but ten years later, the red-moon began it's cycle twelve days earlier than when the cycle begun. The solution to the problem was simple.

A leap week of six day was introduced by the calendar at the end of every quinquennium, regularising the calendar's nine-month year with the solar year and the seasons. These nine months took the names of the most noticeable asterism present in their night sky, and the leap-week, dedicated to all the gods, became an occasion for celebration, feasts and pageantry throughout the kingdom.

The seasons and the festivals associated with them, were kept (as were their names), but the cycle of the white-moon was no longer recorded literally from new moon to new moon. The change of the seasons was set on regular intervals of sixty days when the Athalã worship their gods at the mounds, as they always have.

This way, mound-days fall in the middle of the second, fifth and eight month and at the end of the third, sixth and ninth, with the first, fourth and seventh being months without festivals.