सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)

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E minutes of arc. Then the equatorial rising time of E is
(E × x) / 1800 asus because there are 1800' in a Rasi. We have to
provide a correction in the planetary position including that
of the Sun for this time. If the planet goes Y' during
21659 asus of a day, what arc is covered by the planet or
the Sun in (E × x) / 1800 asus? The result is (E × x) / 1800 × y / 21659
minutes of arc. This correction is positive if the equation
of centre of the Sun is positive, for, we want the planetary
position for a latter time than Mean Sunrise, since the
positive equation of centre advances the True Sun over
the Mean. This correction will be appreciable only in the
case of the Moon having a rapid motion.
Verses 62, 63. The correction known as Udayāntara.
The difference in minutes of arc in the longitude of
the Sāyana mean Sun and the asus in his Right ascension,
multiplied by the daily motion of the planet and divided
by 21659 is the result to be added to or subtracted from
the planet's longitude according as the asus in the Sun's
Right ascension are greater or less than the minutes of arc
of his longitude. This is what is called Udayāntara
correction in the planetary position.
Comm. (1) We have seen that the Bhujāntara is a
correction in the mean planetary position due to the
Equation of time in Eccentricity.
(2) This Udayāntara is a correction in the same
due to the Equation of time in obliquity.
(3) Some have misconstrued that this Udayāntara
correction is the Equation of time in the obliquity itself,
whereas it is a correction to be effected in the planetary
position due to the Equation of time due to obliquity.