Ptolemaic Calendar

The Ptolemaic calendar, developed during the time of the Roman Empire and based on earlier Egyptian systems, is a solar calendar featuring 365 days divided into 12 months. Each of the first 10 months has 30 days, while the last two—Thoth and Paopi—have 35 days each to complete the year. To align with the solar year, an extra day was added every four years, creating a leap year system. While it influenced later calendars, it eventually fell out of use in favor of the Julian and Gregorian calendars, which refined the way we track time today.