SB 3.11.8

लघूनि वै समाम्नाता दश पञ्च च नाडिका ।
ते द्वे मुहूर्तः प्रहरः षड्यामः सप्त वा नृणाम् ॥८॥

laghūni vai samāmnātā
daśa pañca ca nāḍikā
te dve muhūrtaḥ praharaḥ
ṣaḍ yāmaḥ sapta vā nṛṇām

laghūni - such laghus (each of two minutes); vai - exactly; samāmnātā - is called; daśa pañca - fifteen; ca - also; nāḍikā - a nāḍikā; te - of them; dve - two; muhūrtaḥ - a moment; praharaḥ - three hours; ṣaṭ - six; yāmaḥ - one fourth of a day or night; sapta - seven; vā - or; nṛṇām - of human calculation.

Text

Fifteen laghus make one nāḍikā, which is also called a daṇḍa. Two daṇḍas make one muhūrta, and six or seven daṇḍas make one fourth of a day or night, according to human calculation.

Purport

Srimad Bhagavatam. Canto 3: The Status Quo

Chapter 11: Calculation of Time, from the Atom. Text 8

Fifteen laghus make one nāḍikā, which is also called a daṇḍa. Two daṇḍas make one muhūrta, and six or seven daṇḍas make one fourth of a day or night, according to human calculation.