Astrology is the astute study based on scientific calculations of constellations and planetary movements that influence people’s lives. As the markers of time, planetary movements allow people to understand time cycles, from birth till the end of life. One of the important concepts to be studied is Tithis in Astrology. A Tithi is the first phase/portion of the 16 phases of the Moon. It’s a lunar day. There are 15 Tithis in the complete waxing cycle of the Moon (Shukla Paksha or the brighter phase) that commences from Amavasya (the last day of the dark half of a lunar month) and ends at Purnima (Full Moon). Similarly, the other 15 Tithis are a part of the waning cycle of the moon (Krishna Paksha or the darker phase) that starts from the Purnima and ends at Amavasya. When studying astrology by date of birth and astrology predictions, the Tithi is defined based on the correlation between the Sun and the Moon. The first Tithi is 12° of the Moon away from the Sun after the New Moon or Full Moon (Amavasya or Purnima). The second Tithi is the next 12-degree of the Moon away from the Sun. Unlike days that are defined by the Tithi at sunrise, the Tithis can change any time of the day or night as they aren’t defined by the Solar day. There’s no specific good tithi for birth, but all individuals born in specific Tithis have certain qualities as we will see in the following passage. Based on Indian Astrology, Tithi in the birth chart is the time during which the difference of the increment of longitude of the Sun and the Moon amounts to 12. Each Tithi or Lunar day is equal to 0.9483 of a day so that a lunar month when the Moon completes a 360-degree rotation, is equal to about 29.53 days. Tithis in astrology can be found from any horoscope or birth chart if we know the positions of the Sun and Moon in the natal chart. In Indian Astrology, the calculation of the Tithis starts from Pratipada (The first day in each half of the lunar month) of the Shukla-Paksha. Each of the Tithis has a given name, a ruling planet, and can be used in muhurtas for an auspicious event. Astrology predictions state that, based on the movement of the Moon, Tithis vary in duration from approximately 19 to 26 hours.