Sepdt: African Kmt's Calendar Modernized (2023, 339 pages)

Sepdt: African Kmt's Calendar Modernized (2023, 339 pages).  We modernize Kmt's ancient calendar, year and month.

The earliest Kmtian calendar was based on the moon's cycles, but the lunar calendar failed to predict a critical event in their lives: the annual flooding of the Nile river. The Kmtians soon noticed that the first day the "Dog Star," which Kmt called  Sepdt (Sirius), in Canis Major was visible right before sunrise was special. The Kmtians were probably the first to adopt a mainly solar calendar. This so-called 'heliacal rising' always preceded the flood by a few days. Based on this knowledge, they devised a 365-day calendar that seems to have begun around 4241 B.C.E., the earliest recorded year in history.

They eventually had a system of 36 stars to mark out the year and in the end had three different calendars working concurrently for over 2000 years: a stellar calendar for agriculture, a solar year of 365 days (12 months x 30 + 5 extra) and a quasi-lunar calendar for festivals. The later Kmtian calendars developed sophisticated Zodiac systems.