How did chaldeans contribute to our modern calender?

The Chaldeans, particularly the Babylonians, significantly influenced the development of our modern calendar through their use of a lunar-solar system. They divided the year into twelve months, each with a varying number of days, and established a system of intercalation to align their calendar with the solar year. Their innovations in timekeeping and astronomical observations laid the groundwork for later calendar systems, including the Julian and Gregorian calendars we use today. Additionally, the concept of a 60-minute hour and a 360-degree circle, derived from Chaldean mathematics, still permeates our timekeeping and geometric systems.