"With the above logic, why study any Shastra?
Just give everybody a mantra and call it a day.
Jyotish Shastra is extensive and is Shastra, including all Upaya’s from the beginning of time to today. It is a huge Sadhana, one has to do practice (sadhana) everyday and one must have a Ishta Devata.
Jyotish aka Vedic Astrology is a SADHANA, including Tantra Mantra Yantra Sadhana. A sister science to Yoga and Ayurveda. Jyotish means light and its systems are coded in all shastra.
If one does not study Jyotish a 'Vedanga' limb of the Vedas, the eyes of the VEDAS, how can one see the most important words in shastra, all Puja timing is from Jyotish. The same people post it is Shiva Ratri today or Durga Puja tomorrow or when it Kali Puja, duh, how did they know, they know because a Jyotishi calculated it? One of the fist questions one should ask a Guru is what is Kala (time) but first you have to have enough knowledge to even ask that question.
Who is Kala Bhairavia why would you even want to know if you had not even studied kala or TIME that is Jyotish!
Academia has already proved, it does not understand timing of Mahabarat and Ramayan, at least the well educated Jyotish Scientists use Astronomy (Gola) which is part of Jyotish.
Astrology Jyotish and "Oceanography, Geology, seismology, genetics, Hydrology, Climatology, Paleo Botany, Archeology, Agriculture, Domestication, Language, ect to determine the Mahabharat War in 5560 BCE and Ramayan at least 14,000 years ago." Nilesh Oak
It is the study of time, with a whole set of Shastra based on Shastra?
Ravana one of the best known ardent accomplished devotee's of Shiva wrote the Ravan Samhita which is a masterpiece on Jyotish (the art and science light aka Vedic or Indian Astrology.
A few Jyotish Shastra:
Rishi - Parashara Hora Shastra
Brihat Jataka (Varahamihira)
Brihat Jataka - V. Subrahmanya Shastri
Brihaspati sutra, or, The science of politics
Bhrigu Sutras by Rishi Bhrigu
Brihat Jataka by Varahamihira
Daivagyna Vallabha by Varahamihira
Gargahora by Rishi Garga
Saravali by Kalyana Varma
Satya Jataka by Satyacharya
Uttarakalamritam by Kalidasa
Yavana Jataka by Yavanacharya
Nadi Astrology Scriptures
Bhrigu Nadi Nadi by Rishi Bhrigu
Vedic Astrology is called Jyotish a Vedanga or limb of the Vedas, the eyes of the Vedas. Vedas's, Ititihasta (history) and Tantra are all linked together, never let anyone discourage you from studying the whole picture.
Jyotish is a Tantra that is coded in Mahabharat and Ramayan, it is timing, how else does anybody know when it is Shiva Ratri?
Vedic Astrology is not just about future it is a source of all UPAYA's, a good Astrology Jyotish has studied all Shastra. Including and it was fgeven by many Rishi's including Parashara.Jyotish!
Jyotish is the art and science of Light, it is a Tantra and sister science with Ayurveda and Yoga.
It is not a dead log, the person who states it is a dead log is leading light in the wrong direction, Jyotish is a tool to point in the right direction a tool given by the rishi's for not only future but NOW and to determine time in the past.