Which civilization developed and used the first solar calendar?

The first solar calendar was developed and used by the ancient Egyptians. A solar calendar is based on the yearly movement of the Sun, unlike lunar calendars, which follow the cycles of the Moon. The Egyptians closely observed the rising and setting of the Sun and noticed the annual appearance of the star Sirius, which always coincided with the flooding of the Nile River. This natural event was essential for farming because it brought fertile soil to the riverbanks, allowing crops to grow.

The Egyptian calendar divided the year into 365 days, which were organized into 12 months of 30 days each, with an extra five days added at the end of the year. These additional days were called “epagomenal days” and were often linked to religious festivals. This structure allowed the Egyptians to plan agricultural and religious activities more effectively, making their society one of the most advanced of the ancient world.

This solar calendar is considered the first of its kind in human history. It influenced not only the organization of daily life in ancient Egypt but also served as a model for later civilizations. Many modern calendar systems still reflect this Egyptian innovation, especially the idea of dividing the year into 365 days.

Other civilizations mentioned in the options did not create the first solar calendar. The Babylonians mainly followed lunar cycles, the Greeks had mixed systems, and the Aztecs, thousands of years later, developed their own version of a solar calendar. However, the earliest known and widely used solar calendar was created by the Egyptians.

Thus, the correct answer is the Egyptians, who combined astronomy, agriculture, and religion into a highly organized time-keeping system that shaped their civilization.