The first breathe coming out of the body is the one we must look for because breathe is a unit of time measure as per the Rishis.

Yoga system calculates number of breaths an individual makes in a day as per the following: 60 Truth =1 Praana ( 1 inhale + 1 exhale ) 6 Praanas =1 Vinaadi 60 Vinaadi =1 Ghati 60Ghatis = 1day

Therefore man breaths, 60x60x6=21600 times in a day. This is given in Patanjalis Yogashastra.

The first breathe coming out of the body is the one we must look for because breathe is a unit of time measure as per the Rishis.

The below is from Surya Siddhanth : Chapter 1 verse 12 in Phanindra Ganguly's translation.

12. And sixty nadis make a sidereal day and night....

The manuscripts without commentary insert, as the first half of v. 11, the usual definition of the length of a respiration: " the time occupied in pronouncing ten long syllables is called a respiration. '

The table of the divisions of sidereal time is then as follow: 10 long syllables (gurvaftshara) = 1 respiration (prana, period of four seconds); 6 respirations = 1 vinadi (period of twenty-four seconds); 60 vinadis = 1 nadi (period of twenty-four minutes); 60 nadis = 1 day.