SB 3.11.14
samvatsarah parivatsara
ida-vatsara eva ca
anuvatsaro vatsaras ca
viduraivam prabhasyate
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
There are five different names for the orbits of the sun, moon, stars and luminaries in the firmament, and they each have their own samvatsara.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The subject matters of physics, chemistry, mathematics, astronomy, time and space dealt with in the above verses of Srimad-Bhagavatam are certainly very interesting to students of the particular subject, but as far as we are concerned, we cannot explain them very thoroughly in terms of technical knowledge. The subject is summarized by the statement that above all the different branches of knowledge is the supreme control of kala, the plenary representation of the Supreme Personality of Godhead. Nothing exists without Him, and therefore everything, however wonderful it may appear to our meager knowledge, is but the work of the magical wand of the Supreme Lord. As far as time is concerned, we beg to subjoin herewith a table of timings in terms of the modern clock.
One truti — 8/13,500 second
One vedha — 8/135 second
One lava — 8/45 second
One nimesa — 8/15 second
One ksana — 8/5 second
One kastha — 8 seconds
One laghu — 2 minutes
One danda — 30 minutes
One prahara — 3 hours
One day — 12 hours
One night — 12 hours
One paksa — 15 days
Two paksas comprise one month, and twelve months comprise one calendar year, or one full orbit of the sun. A human being is expected to live up to one hundred years. That is the way of the controlling measure of eternal time.
The Brahma-samhita (5.52) affirms this control in this way:
yac-caksur esa savita sakala-grahanam
raja samasta-sura-murtir asesa-tejah
yasyajñaya bhramati sambhrta-kala-cakro
govindam adi-purusam tam aham bhajami
“I worship Govinda, the primeval Lord, the Supreme Personality of Godhead, under whose control even the sun, which is considered to be the eye of the Lord, rotates within the fixed orbit of eternal time. The sun is the king of all planetary systems and has unlimited potency in heat and light.”