As-cen-sion-al Time
/əˌsɛnʃənəl taɪm/
The period it takes for an entire 30-degree zodiac sign to rise above the eastern horizon at a specific geographic latitude.
Because the ecliptic—the Sun’s apparent path around the Earth—is tilted relative to the celestial equator, each zodiac sign rises at a different rate depending on the observer’s latitude. Signs near the celestial poles appear to rise very slowly, while equatorial signs rise more quickly. This difference in the rate of rising is known as Oblique Ascension.
In Hellenistic astrology, Ascensional Time (Greek: anaphoros chronos, “rising time”) was used to describe these varying rising periods for zodiacal signs and degrees. It helps explain the unequal lengths of astrological “hours” and the differing durations of signs on the Ascendant across locations. However, Ascensional Time itself does not determine which sign is rising—it measures how long that sign takes to ascend, not what sign is on the horizon.