Sarvāṅgasundarā
tatra ṛtuviśeṣān lakṣayati- māsairiti| dvisaṃkhyairiti ṣaṭkṛtvā āvartyaikaśeṣaḥ kartavyaḥ| tatra māghaphālgunau-śiśiraḥ, caitravaiśākhau-vasantaḥ, jyeṣṭhāṣāḍhau-grīṣmaḥ, śrāvaṇabhādrapadau-varṣāḥ, āśvinakārtikau-śarat, mārgaśīrṣapauṣau-hemantaḥ| nanu suśrutena bhādrapadādyairvarṣādaya ṛtava uktāḥ| tadyathā (su.sū.a. 6/10)- "bhādrapadāśvayujau-varṣāḥ , kārtikamārgaśīrṣau-śarat,pauṣamāghau- hemantaḥ, phalgunacaitrau-vasantaḥ, vaiśākhajyeṣṭhau-grīṣmaḥ, āṣāḍhaśrāvaṇau-prāvṛṭ " iti| iha tvanyatheti virodhaḥ| maivam| na hi phalgunacaitrau-vasantaḥ nāpi caitravaiśākhau| kintu mīnameṣau| yadā phālgunādau mīnasaṅkrāntistadā phalgunacaitrau-vasantaḥ,yadā tu phālguṇānte tadā caitravaiśākhau| evaṃ vṛṣamithunau- grīṣmaḥ, karkaṭasiṃhau-varṣāḥ, kanyātule-śarat, vṛṣcikadhanuṣī-hemantaḥ, makarakumbhau-śiśiraḥ, iti| uktaṃ ca jyotiḥśāstre- "mṛgādirāśidvayabhānubhogāt ṣaḍartavasyuḥ śiśirovasantaḥ| grīṣmaśca varṣāśca śaracca tadvaddhemantanāmā kathito+atra ṣaṣṭhaḥ||" varṣāyanartuyugapūrvakamatra saurāditi ca| sauraśca māsastatraivoktaḥ-" darśāvadhiṃ māsamuśanti cāndraṃ, sauraṃ tathā bhāskararāśibhogāt| triṃśaddinaṃ sāvanasaṃjñamāryā,nākṣatramindorbhagaṇabhramācca|" iti| avaśyaṃ caivamaṅgīkartavyam, anyathā adhimāsanipāte māsatrayamṛtuḥ syāt| saṅgrahe tu (sū.a.4)-"māsarāśisvarūpākhyamṛtoryallakṣaṇatrayam| yathottaraṃ bhajeccaryāṃ tatra tasya balāditi" iti| māsalakṣaṇādrāśilakṣaṇaṃ balavat, ato rāśilakṣaṇamevāṅgīkṛtam, svarūpalakṣaṇasya ṛtuviparyayaparyavasānāt| uktaṃ hi tatraiva (saṅgrahe sū.a.4)-ṛtuṣvevaṃvidheṣveva vidhiḥ svāsthyāya dehinām| nirdiśyate+anyarūpeṣu viruddhajñāniko vidhiḥ| " iti| tasmācchiśiraṣaṭkaprāvṛṭṣaṭkayoḥ saṃjñāmātreṇaiva bhedaḥ| saṃjñābhedaṃ ca deśabhedenāha kāśyapaḥ-"bhūyo varṣati parjanyo gaṅgāyā dakṣiṇe taṭe| ataḥ prāvṛṭ ca varṣāśca ṛtū tatra prakalpitau|| tasyā evottare deśe himavadvindhyasaṅkule| bhūyaḥ śītamatastatra hemantaśiśirāvubhau||" iti| dakṣiṇadeśīyairvṛṣṭisaṃbandhinordvayoḥ prāvṛḍvarṣākhyatvaṃ kṛtvā, pāriśeṣyācchītasambandhinordvayoḥ śaraddhemantākhyatvaṃ kṛtam| uttaradeśīyaistu śītasambandhinordvayorhemantaśiśirākhyatvaṃ kṛtvā, pāriśeṣyādvṛṣṭisambandhinordvayorvarṣāśaratsaṃjñatvaṃ kṛtamityarthaḥ| vṛṣṭiśītabāhulyopanyāsastatrānvarthasaṃjñārthaḥ , na ca saṃjñāsaṅkare lakṣaṇasaṅkaraḥ, doṣāṇāṃ doṣadhātumalasaṃjñāvat| anye punarbhedaṃ manvānāannarasān balaṃ cādhikṛtya śiśiraṣaṭkam, cayādīn śodhanaṃ cādhikṛtya prāvṛṭṣaṭkam, iti vyavasthāpayanti| tadasat| carakakhāraṇādiprabhṛtibhiḥ śiśiraṣaṭkamevādhikṛtya cayādīnāmuktatvāt| śodhanasyatu caitraśrāvaṇakārtikeṣu vidhānnānna ṛtvapekṣā| ṛtvapekṣāyāmapi sādhāraṇartūnāṃ śiśiraṣaṭkepi vidyamānatvānna prāvṛṭṣaṭkāpekṣā| anyetu gaṅgāyā dakṣiṇe vṛṣṭibāhulyāt prāvṛṭṣaṭkam, uttare śītabāhulyāt śiśiraṣaṭkam, iti vyavasthāpayanti| tadapyasat ubhayatrāpi cāturmāsikavṛṣṭiśītopalaṃbhāt, āśvine divyodakagrahaṇasyobhayadeśaviṣayatvācca| bhedapakṣe hyuttaradeśe tadanārtavaṃ syāt| yattu suśrutasya (u.a.64/45)-"tāpātyaye hitā nityam" ityādi,varṣācaryāyāḥ pṛthak prāvṛṭcaryābhidhānam, tadatidurdinaviṣayam| tathā ca carakaḥ (sū.a.6/36)-" vyaktāmlalavaṇasnehaṃ vātavarṣākule+ahani| viśeṣaśīte bhoktavyaṃ varṣāsvanilaśāntaye|| " iti| ata eva suśrutena tāpātyayaśabdaḥ prayuktaḥ| tāpasya- arkaprakāśasya, atyayaḥ- atyantāpagamaḥ, sa cātidurdina eva, iti sarvaṃ samañjasam| tasmādvāgbhaṭācāryābhimatamabhedapakṣamevāśrayadhvamiti| prathamartutrayasya saṃjñādvayamāha-tribhiriti| taiḥ-śiśirādyaistribhiḥ, uttarāyaṇamādānaṃ ca vidyāt| ādānasajñāṃ nirvakti- tadādatta iti| tat-śiśirāditrayaṃ, nṛṇāṃ pratidinaṃ balamādatte, iti ādānam| balavisargaṃprati saumyatvasya hetutvenopādānāt balādānaṃ prati āgneyatvasya hetutvaṃ jñeyam|