Skandapurana 5.47.210_23

5.47.210_23

adya puṇyatithirnāma vaiśākhī puṇyadā parā ..
yasyāmasya puro bhaktyā naraḥ kuryātprajāgaram ..
mahākālasya devasya saukhyaṃ prāpnotyasaṃśayam .. 44 ..

Today is the auspicious lunar day named the full moon of Vaiśākha, granting supreme merit, / on which, if a man keeps vigil before this god Mahākāla / with devotion, he attains happiness without doubt.”