Acmana

Acmana is a term used in Vedic astrology (Jyotisha) to denote a specific unit of time. It is a relatively short duration, smaller than a Muhurta. While definitions can vary slightly across different sources, it's generally understood as a fraction of a lunar day (tithi).

The precise length of an Acmana can be derived from the calculation of Tithis. A Tithi is the time it takes for the longitudinal angle between the Sun and the Moon to increase by 12 degrees. As a Tithi can vary in length, so too does the Acmana. However, it is commonly expressed as a fixed fraction of a Muhurta. A Muhurta itself is usually defined as 48 minutes. The number of Acmanas per Muhurta can vary, leading to differing estimations of its duration. It is not a widely used unit of time in common practice, as larger units like the Muhurta and smaller units used in mantra recitation and rituals are more prevalent. The term is primarily relevant in the context of precise time calculations for specific astrological purposes, such as determining auspicious timings for rituals or analyzing the subtle effects of planetary positions. The importance lies in the potential for accurate astrological calculations, though its precise application is more commonly found within scholarly circles studying ancient Vedic texts and their astrological interpretations.