Yoga

In panchang terminology, a yoga is calculated by adding the true sidereal longitudes of the Sun and Moon and dividing the sum by 13°20'. This produces one of 27 yogas, each spanning a 13°20' arc. Unlike nakshatra (which depends only on the Moon) or tithi (which depends on the Sun-Moon difference), yoga reflects the combined angular relationship of both luminaries.

The 27 yogas range from highly auspicious to inauspicious. Siddhi, Amrita, and Shubha yogas are considered excellent for initiating new ventures, while Vyatipata, Vaidhriti, and Vishkumbha are regarded as challenging and are generally avoided for important activities. The quality of a yoga directly influences the overall auspiciousness of a given time window and is always considered alongside tithi and nakshatra when selecting a muhurat.

Tithimala computes the yoga by obtaining the Sun's and Moon's true sidereal longitudes from Swiss Ephemeris, summing them (modulo 360°), and determining which 13°20' segment the sum falls into. Since both the Sun and Moon are continuously moving, the yoga changes at irregular intervals — typically lasting between 20 and 28 hours depending on the Moon's orbital speed at that point in its cycle.

Yoga is one of the five limbs (pancha-anga) of the traditional panchang. While it receives less popular attention than tithi or nakshatra, experienced jyotishis consider it an essential factor, particularly for marriage muhurat, griha pravesh, and business inaugurations.