Declension table of ?mahāśivarātri

Feminine	Singular	Dual	Plural
Nominative	mahāśivarātriḥ	mahāśivarātrī	mahāśivarātrayaḥ
Vocative	mahāśivarātre	mahāśivarātrī	mahāśivarātrayaḥ
Accusative	mahāśivarātrim	mahāśivarātrī	mahāśivarātrīḥ
Instrumental	mahāśivarātryā	mahāśivarātribhyām	mahāśivarātribhiḥ
Dative	mahāśivarātryai mahāśivarātraye	mahāśivarātribhyām	mahāśivarātribhyaḥ
Ablative	mahāśivarātryāḥ mahāśivarātreḥ	mahāśivarātribhyām	mahāśivarātribhyaḥ
Genitive	mahāśivarātryāḥ mahāśivarātreḥ	mahāśivarātryoḥ	mahāśivarātrīṇām
Locative	mahāśivarātryām mahāśivarātrau	mahāśivarātryoḥ	mahāśivarātriṣu

Compound mahāśivarātri -

Adverb -mahāśivarātri