Matsyapurana 141.33

141.33

tasmāttu parvaṇo hyādau pratipadyādisaṃdhiṣu
sāyāhne anumatyāśca dvau lavau kāla ucyate
lavau dvāveva rākāyāḥ kālo jñeyo 'parāhṇikaḥ //

Now the periodical junctions, Parva Sandhis will be described These are like the knots of a bamboo or a sugarcane joined to one another in a circle The year, the months, the dark and the bright fortnights and the full moon night are the knots and junctions and the Tithis, the second, third, and so on, form the parvas of the fortnight The Agnyâdhân or the maintenance of the sacred Fire ought to be done in this Parva Sandhi The periodical junction of the Anumati or Rakâ with Pratipadâ lasts for only two lavas (in the afternoon) The Pratipadâ of the dark fortnight occurs in the afternoon and if it occurs in the evening it is called the period of Pûrṇamâsi—29 33