Why were ancient daylight hours longer in summer than in winter?

In ancient timekeeping, the perception that daylight hours were longer in summer than in winter was a result of the use of seasonal hours (also known as temporal hours) rather than a change in the physical nature of time itself.12

Ancient civilizations, including the Egyptians, Greeks, and Romans, typically divided the period of daylight into 12 equal intervals, regardless of the time of year. Because the actual duration of sunlight varies significantly by season—reaching its maximum in summer and its minimum in winter—these 12 subdivisions necessarily varied in length to fit the available daylight. Consequently, an "hour" of daylight in the summer was physically longer than an "hour" of daylight in the winter.132

This seasonal variation in daylight duration is caused by the tilt of the Earth's axis relative to its orbital plane. As the Earth orbits the Sun, this tilt results in more hours of sunlight in the hemisphere inclined toward the Sun and fewer in the hemisphere inclined away. These variable hours remained the standard until the development of mechanical clocks in the 14th century, which eventually popularized the use of equal, fixed-length hours.4532