Pracetassmriti 1.4: Kālaviveka · Kālanirṇaya (Kālamādhavīya) · Kālanirṇaya +2

1.4

ekādaśī pravṛddhā cec chukle kṛṣṇe viśeṣataḥ | tatrottarāṃ yatiḥ kuryāt pūrvām upavased gṛhī

If the eleventh lunar day (Ekādaśī) is extended, especially in the bright or dark fortnight, / the ascetic should observe the subsequent one, while the householder should fast on the preceding one.

If the eleventh is extended, in the bright and especially in the dark fortnight, the ascetic should keep the later day, the householder fast on the earlier.