Śrīmad-Bhāgavatam · Text 11.21.9
Who is speaking and story frame
कर्मण्यो गुणवान् कालो द्रव्यत: स्वत एव वा ।
यतो निवर्तते कर्म स दोषोऽकर्मक: स्मृत: ॥ ९ ॥
karmaṇyo guṇavān kālo
dravyataḥ svata eva vā
yato nivartate karma
sa doṣo ’karmakaḥ smṛtaḥ
A specific time is considered pure when it is appropriate, either by its own nature or through achievement of suitable paraphernalia, for the performance of one’s prescribed duty. That time which impedes the performance of one’s duty is considered impure.
Read the purport on Vedabase.ioFrom Canto 10, chapter 14 onward, the translation and purports were completed by Śrīla Prabhupāda's disciples after his departure, and published by the Bhaktivedanta Book Trust.