poeple in different parts of India follow different calendar.
They all are Hindu calendars but are different from each other. You
might want to have a look at saka calendar.
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Chaitra Masa is the first month in Hindu Calender.
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Unfortunately, I am quite unsure of the exact question you are
asking. If you are asking what the Hindu months are called, they
are as follows: Chaitra, Vaisakha, Jyestha, Ashadha, Shravan,
Bhadra, Ashwina, and more if it's a leap year.