Was a day divided in 24 hours in Ancient India?

[Raja Roy]

Prāchyam has released a video on May 12, 2022 titled “Ancient Indian Logic for Sequence of Weekdays”. Here is the link to the video: https://www.youtube.com/watch?v=1Pz9L7PDmg4.

In this video, Prāchyam claims that a verse from Śrīmadbhāgvatam describes the division of a day in 24 hours. Though Prāchyam does not give the exact reference for this verse, it is given in a talk by Mr. Nilesh Oak. Prāchyam’s video is based on this talk by Mr. Oak titled “The Secret of Weekday Sequence”. Here is the link to this talk by Mr. Oak: https://www.youtube.com/watch?v=L0Gs_S13vfw. Mr. Oak gives the exact reference as Śrīmadbhāgvatam 3.11.7–8. Sanskrit text and Hindi translation by Gītā Press for these verses are given below:

According to these verses, two “nāḍikā” equal one “muhūrta” and there are six or seven nāḍikā in one “Prahara”. 

Nāḍikā, muhūrta, and Prahara are well known divisions of time in Ancient India. According to Vedāṅga Jyotiṣa, there are two nāḍikā in one muhūrta and there are 30 muhūrtas in a day and night (Ṛk Vedāṅga Jyotiṣa 16, Yajus Vedāṅga Jyotiṣa 38). Thus, one nāḍikā equals 24 minutes and one muhūrta equals 48 minutes. But Mr. Oak claims that one muhūrta equals 60 minutes according to Śrīmadbhāgvatam 3.11.7–8 and hence ancient Indians had invented the division of the day in 24 hours. Here is the screenshot from his talk at t=41:38 [https://www.youtube.com/watch?v=L0Gs_S13vfw]:

 

Mr. Oak puts 7 in round brackets and neglects it. He chooses 6 nāḍikā conveniently and equates it to one Prahara of three hours. Thus, he claims that one nāḍikā equals 30 minutes and one muhūrta equals 60 minutes, and therefore ancient Indians invented the division of a day in hours. 

However, Prahara was not of fixed duration and depended on the season. In fact, its duration changed between daylight period and night period of the same 24-hour duration from one sunrise to the next sunrise. The Prahara during day time was one fourth of the duration of daylight period and the Prahara during night was one fourth of the night duration. We have an explicit scheme given in the commentary on Śrīmadbhāgvatam by Śrīdhara Swāmī and full explanation of this commentary is provided in a research paper by Prof. Takao Hayashi [Takao Hayashi. “The Units of Time in Ancient and Medieval India.” History of Science in South Asia, 5.1 (2017): 1–116.].

In this scheme of Śrīmadbhāgvatam, a 24-hour period of one sunrise to next sunrise was divided into day of 4 prahara (24 nāḍikā, 6 nāḍikā per Prahara), dusk of 2 muhūrta (4 nāḍikā, 2 nāḍikā per muhūrta), night of 4 prahara (28 nāḍikā, 7 nāḍikā per Prahara), and dawn of 2 muhūrta (4 nāḍikā, 2 nāḍikā per muhūrta). This was valid in winter. The corresponding passage from the research paper by Prof. Takao Hayashi is shown below:

Prof. Takao Hayashi has also beautifully illustrated this division in the following figure. Please note the explicit mention of 1 prahara being equal to 6 nāḍikā during day and 1 prahara being equal to 7 nāḍikā during night.

Thus a 24-hour period of one sunrise to next sunrise consisted of 60 nāḍikā of 24 minutes duration each or 30 muhūrta of 48 minutes duration each. Śrīmadbhāgvatam 3.11.7–8 does not describe the division of the day in 24 hours. Prachyam is clearly wrong in their claim that Śrīmadbhāgvatam describes the division of the day into 24-hours.

Best regards,

Dr. Raja Roy

(This is a shortened version of my article on medium.com: Was a day divided in 24 hours in Ancient India? | by Dr. Raja Ram Mohan Roy | May, 2022 | Medium | Medium)