Themiclesian calendar

The Themiclesian calendar is a lunisolar calendar employed in Themclesia for certain legal, administrative, and social purposes. Though largely supplanted by the Gregorian calendar in the 19th century for commerce, the Themiclesian calendar is still used for cultural events, fortune-telling, and numerous other purposes. It enjoys co-official status with the Gregorian calendar though limited actual use.

Lunar month

The lunar month is based on the phases of the moon. Rather than following a single cycle that encompasses the whole gamut of the moon's phases, there are two simultaneous cycles that point to various parts of the month.

The first cycle, and probably the more ancient, recognizes two points in the moon's phases, the new crescent moon (朏, pei’ or pjei’) and the first day past full moon (既望, kjeis-mjangs). The crescent moon has been defined as the third day of a month when the previous month was 29 days, or the second day when the prevoius had 30. The full moon is always 15 days exactly from the crescent. It has been noted as an anomaly that the crescent moon is not adopted as the first day of each month, rather the first moonless day. Scholars studying bronze inscriptions unearthed in Menghe have suggested that, prior to the 9th century BCE, it was indeed the crescent moon that heralded the commencement of the new month. The shift of the beginning of the month probably indicates the detachment of the calendar from actual astronomical observations, which in turn indicates the development of a mathematical understanding of the movement of the celestial bodies that function as timepieces.

The second cycle recognizes four other points in a lunation. The first is the moonless night (朔, sngrak) following the waning crescent of the previous lunation. The day following (既死霸, kjeis-sji'-pras), if the previous month was 29 days, is given special standing. Bronze inscriptions further indicate this term should be synonymous with the moonless night, but in Themiclesia its meaning has shifted to the day following. The eighth day of each lunation is termed the waxing crescent, regardless of the length of the previous month 既生霸 方死霸 晦