दिवसानुवृत्तो नित्यः ॥ कZ_०२.६.२४ ॥
divasānuvṛtto nityaḥ
यो दिवसानुदिवसमनुवर्तते स नित्यः (आयः)॥
It provides a simple operational test for classifying receipts as routine cashflow versus periodic or exceptional receipts.