Mudgalapurana 4.1.54

4.1.54

ekakālaṃ dvikālaṃ vā trikālaṃ labhate sadā |
avratī vratasāphalyaṃ paṭhanānnātra saṃśayaḥ ||

One who lacks vows always attains the fruit of vows by reciting [it]
once, twice, or thrice [a day]; there is no doubt about this.”