Suryasiddhanta 2.69

2.69

saptānāṃ carakaraṇānāṃ pratyekaṃ tithyantaścāsau bhogaśca taṃ tithyarddhakālamitāvasthānaṃ prakalpayet | ekatra nirṇītaḥ śāstrārtho'paratra bhavatīti nyāyāt karaṇatvenaiṣāmapyavasthānaṃ tattulyaṃ kuryyādityarthaḥ | ata eva tithyarddhaṃ karaṇaṃ smṛtamityuktyā cāndramāse triṃśattithyātmake ṣaṣṭikaraṇṇānāṃ sanniveśāntarakaraṇānāmeva paribhramaṇe pratimāsamaniyatatithibhogakaṃ karaṇaṃ bhavatīti taddārakapratimāsaniyatatithibhogakakaraṇakasiddhyarthaṃ carakaraṇānāmaṣṭavāraparibhramaṇottaramavaśiṣṭatithyoścaturdhardheṣu sthirakaraṇānyuktānīti tātparyam | tatrāpi kṛṣṇacaturdaśyaparārdhatastatkalpanaṃ tadicchāniyāmakaṃ svatantrecchasya niyogānarhatvāt | athāgrimagranthāsaṅgatitvanirāsārthamuktādhikāramupasaṃharati | eṣeti | he maya sūryādīnāṃ saptagrahāṇāmeṣā dṛgvetyādi kalpayedityantaṃ yā vārtā sā sphuṭagatiḥ spaṣṭagatiḥ spaṣṭa kriyājñānasampādikā proktā tubhyaṃ mayoktā | etena spaṣṭādhikāraḥ paripūrttimāpta iti sūcitam |