Introduction:

Time, as a concept, has been central to human civilization. Its perception and measurement have evolved dramatically, with early cultures like the Egyptians, Mayans, and Greeks laying foundational ideas that still impact our understanding today.

Egyptians:

• Solar & Lunar Calendars: The Egyptians based their calendar on the lunar cycle but adjusted it to the solar year. They had a 365-day calendar based on the heliacal rising of the star Sirius.
• Sundials & Water Clocks: To measure daily time, they utilized shadows cast by obelisks (early sundials) and later invented water clocks for more precise measurements.
• Impact: The modern 365-day calendar owes its basis to the Egyptian solar year.

Mayans:

• Tzolk'in & Haab': The Mayans had a complex calendar system. Tzolk'in was a 260-day ceremonial calendar, while Haab' was a 365-day solar calendar.
• Long Count: This was their linear count of days from a starting point, which many believe correlates to August 11, 3114 BCE.
• End-of-the-World Myth: The end of a Mayan calendar cycle in 2012 led to modern myths about the apocalypse.
• Impact: The Mayan emphasis on cyclical time, with its cycles within cycles, has parallels in modern discussions on time's nature.

Greeks:

• Cyclical vs. Linear Time: Ancient Greeks had two words for time: 'Chronos' (sequential time) and 'Kairos' (the opportune moment). This distinction showcases their understanding of both cyclical and linear time.
• Water Clocks: The Greeks advanced the Egyptian concept, using them especially in law courts to limit the length of arguments.
• Platonic Year: Based on the precession of the equinoxes, it's roughly 26,000 years long.