Why do Hindu festivals fall on different dates every year?
How festivals are determined?
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Sign up to join this communityWhy do Hindu festivals fall on different dates every year?
How festivals are determined?
They do not fall on different dates. It appears as falling on different dates only if we are not following the Hindu calendar.
How festivals are determined?
They are determined by Hindu months and Tithis etc.
For example this is how when to celebrate Navaratri festival is determined:
6-8. O king! The people are very much afflicted with various terrible diseases in these two seasons autumn and spring and many lose their lives during these portions of the year. Therefore the wise should unquestionably worship with great devotion the Chandikâ Devî in these auspicious months of Chaitra and Âs’vin.
9-11. On the day previous to the commencement of the vow, when the Amâvasyâ tithi commences, one should collect the materials that will be required in the worship and should eat only once in that tithi what is called Habisyânna (sacred food, boiled rice with ghee)
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12-17. One should invite then, those Brâhmins, that observe fully the customs and usages, who are self restrained and versed in the Vedas and Vedângas, especially those who are skilled in the ceremony of worshipping the Devî. Next, in the Pratipad tithi (the first day of the bright half), one should take one’s morning ablutions in a river, or in a lake, tank or a well or in one’s own residence, according to rules, and one should perform one’s every day practices of Sandhyâ Vandanam.
From Devi BhAgavatam Book 3, Chapter 26.
So, in the month of Aswin or Chaitra, the preparations for the festival must begin on the Amavasya Tithi and the actual celebrations should start from the Pratipada Tithi and then continue for nine subsequent days.
So, in this way, each year these dates remain the same as per the Hindu calendar. Now, if we are following some other calendars, then obviously the dates will vary with year.
The same argument holds for any other festivals. For, example, the MahAshivarAtri falls each Hindu year on Krishna Chaturdashi of the Magha month. Now, this day will appear as falling on different dates only if we are following calendars other than the Hindu calendar.