In the last post I presented an interactive model of the prcession of the equinoxes that helps visualize the analysis carried out by Bal Gangadhar Thilak and presented in “The Orion, or a Research into the Antiquity of the Vedas”.
Consider the following references in the Taittriya Samhitha:
There are many passages in the Taittriya Sanhita, the Taittiriya Brahmana and other works where the Krittikas occupy the first place in the list of the Nakshatras…granting that the Krittikas were the mouth of the Nakshatras in the sense that their list always commenced with them, it may be asked what position we are to assign to the Krittikas in the course of the year. We cannot … place the summer solstice in the Krittikas, unless we are prepared to take back the composition of the Taittiriya Sanhita to about 22,000 B. C…the same thing may be said against placing the Krittikas in the autumnal equinox…it is more natural to presume that the vernal equinox coincided with the Krittikas at the time when the Taittirlya Sanhita was compiled. – The Orion, pp. 39 – 41.
Furthermore:
Supposing the Krittikas to denote the asterism of that name this gives us, according to Prof. Whitney’s calculation, 2350 B. C. as the probable time for the compilation of the Taittirya Sanhita…Now as the position of the asterism of the Krittikas in its zodiacal portion is 10 50′ from the beginning…” – The Orion, pp. 55.
And also:
…the Nakshatras of the Devas begin with the Krittikas and end with Vishakha, whereas the Nakshatras of Yama begin with the Anuradhas and end with the Apa-Bharanis.” – The Orion, pp. 41.
Now peruse the following figure which illustrate the positions of the equinoxes and solstices which satisfy all the above references, and indicates 2350 BC as being the year when these positions last occurred:

As the model indicates, this time period corresponds to the Mature period of the Harappan civilization, which leads us to observe one more interesting correlation, as follows:
The nakshatra of Krittika is identified with the open star cluster of Pleiades which consists of nine bright stars. In Hindu mythology Krittika is associated with the seven wives of the Sapta Rishis (the seven sages). Greek mythology too associates Pleiades with the number seven by calling it “The Seven Sisters”.
Now let us switch to the Mature Harappan civilization, and consider this well-known artifacts of that period. It clearly shows seven women leading to a speculation this seal refers to Krittika during a period when our model shows that the year began with the vernal equinox in Krittika! Pure speculation, yes, but interesting speculation nonetheless.