Tithididhiti 1.31.p1.9

1.31.p1.9

dinadvaye karmakālavyāptau yugmaśāstrānnirṇaya iti hemādrau madranaratne ca | yatra sāṅgaikabhaktaprayoge uktamukhyakālo gauṇānapekṣo
na paryāpnoti tatra pūrvaiva tithiḥ, yatra paryāptastatra yugmavākyānnirṇaya iti matayorvyavasthā | ityekabhaktanirṇayaḥ
naktaṃ sauraṃ ravivāsarasaptamyādau vihitaṃ sāyāhne kāryam
ye tvādityadine brahmannaktaṃ kurvanti mānavāḥ
dinānte te'pi bhuṃjīranniṣedhādrātribhojane | iti
bhaviṣyottaravacanāt, narasya dviguṇāṃ chāyāmatikrāmedyadā raviḥ
tadā sauraṃ bhavennaktaṃ na naktaṃ niśi bhojanam | iti kaurmokteśca
anyadapi yatīnāṃ sāyāhna eva kāryam-nakṣatradarśane naktaṃ gṛhasthasya
vidhīyate | yaterdināṣṭame bhāge tasya rātrau niṣidhyate iti
devalavacanāt | ata uktavidhādvaye'pi sāyāhnavyāpinī tithirgrāhyā | uktānyanakte pradoṣavyāpinī grāhyā-trimuhūrtaḥ pradoṣaḥ
syādbhānvāvastaṃgate sati | naktaṃ tatra ca kartavyamiti śāstraviniścayaḥ | iti vyāsokteḥ | astātprāktano muhūrto gauṇaḥ
kālaḥ-muhūrtondiṃnaṃ naktaṃ pravadanti manīṣiṇaḥ | nakṣatradarśanānnaktamahaṃ manye gaṇādhipa-iti bhaviṣye paramatatvena tasya gauṇatvasūcanāt | dinadvaye pradoṣavyāptau parā grāhyā-yadi syādubhayostithyoḥ pradoṣavyāpinī tithiḥ | tadottaratra naktaṃ syādubhayaḥ
trāpi sā yataḥ | iti jābālivacanāt | ubhayatra divārātrau
evaṃ dinadvaye pradoṣaikadeśavyāptāvapi | dinadvaye pradoṣasaṃbandhābhāve tūttaratra sāyāhne naktaṃ kāryam-pradoṣavyāpinī na syāddivā
naktaṃ vidhīyate | ātmano dviguṇā chāyā mandībhavati bhāskare