

Shia Jantri
Salam, my dear brothers and sisters. I hope you are all well.
I had a question and was hoping someone with more knowledge on the subject could shed some light on it.
I’ve always been somewhat sceptical about books such as the Jantri. I come from a Pakistani background, and I know that in many Pakistani households these books are commonly used and relied upon, particularly when determining whether certain dates or days are considered good, bad, auspicious or inauspicious.
I wanted to understand the basis behind this. Do Shia communities from other cultures and countries have similar books or practices, or is the Jantri mainly something found within the subcontinent?
More importantly, what is the religious validity of these books? How exactly is it determined that a particular date is “good” or “bad” for things such as marriage, travel, starting something new, etc.? Is there evidence for these conclusions from the Qur’an, hadith or teachings of the Ahlulbayt (a.s.), or are some of these practices based more on cultural traditions, astrology or later calculations?
I’m not asking to criticise the practice at all; I’m genuinely interested in understanding where it comes from and what evidence it is based upon.
JazakAllah khair, and I’d really appreciate any references or explanations anyone can share.