How yoga is calculated
Nitya yoga is calculated from the sum of the Sun’s and Moon’s sidereal longitudes, divided into 27 equal intervals.
Yoga, one of the five parts of the panchangam, comes from adding the Sun's and Moon's positions along the sidereal zodiac, measured in degrees. If the total is 360 degrees or more, subtract 360 degrees.
The resulting value is placed within one of 27 intervals, each spanning 13 degrees 20 minutes. That interval determines the yoga, from Vishkambha through Vaidhriti.
When the yoga changes
As the Sun and Moon move, their combined longitude reaches the next interval. The time of that crossing is the yoga's ending time shown on the daily page.
Why ayanamsha matters
Ayanamsha is applied to both longitudes before they are added. A different ayanamsha convention can therefore change the yoga's ending time. Comparisons between calendars should use the same convention.
How it is used
In traditional muhurta selection, yoga is considered together with the other parts of the panchangam and the nature of the intended activity.