To ascertain the precise time for undertaking Svādhyāya (scriptural studies and teaching) (in conformity with the method given in the Āgamas (canonical works)) etc...
āgamavidhinā yathāvannirūpaṇā grahanapratijāgaraṇarūpā kālapratyupekṣaṇā.
(U 29.16 ŚāVṛ Pa 583)