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

30
supposing that the number of the elapsed years contain
three luni-solar years after the year carrying the last inter-
calary month, the error in construing them to be solar will
be roughly minus one solar month. In other words the
difference between three mean solar years and three luni-
solar years will be roughly one solar month. Since one
Adhikamāsa occurs roughly in 32½ solar months, so the
number of Adhikamasas obtained by construing three luni-
solar years as mean Solar years will be in default by roughly
1/32½ or 2/63. As we are counting only the integral number
of Adhikamāsas obtained as a quotient rejecting the
remainder, the above default of 2/63 should not normally
effect the quotient. Most rarely, however, it might effect
the quotient by one, for which provision is made by Bhas-
kara in verse 3 under Adhimāsādinirṇaya section, Madhya-
mādhikara namely स्पष्टोऽधिमासः पतितोपलब्धः etc. which
means that if the quotient is in default by one, where it
is definitely known that one more Adhikamāsa did occur,
we are directed to add one and if we certainly know that
the quotient contains one more Adhikamāsa, when the
Adhikamāsa is shortly to occur and has not occrued we
are directed to substract one from the quotient. This
principle of सैकत्वनिरेकत्व is to be observed even in the
context of Kshayāhas ie we are directed to add one or
subtract one from the number of civil days by adjusting
the Ahargaṇa to the week-day on which the Ahargaṇa is
sought to be found.
Thus construing the elapsed number of years to be
solar, multiplying them by twelve we have the elapsed
solar months. Adding to this the number of the elapsed
luni-Solar months construing these to be solar, which fact
also does not affect normally the number of Adhikamāsas to
be obtained (for the same reason above) and multiplying by
30 and adding the elapsed tithis we have the elapsed num-
ber of solar days (This number may not be exactly the