Question

What is the base of naming the Indian months? Write the name of the Indian months and describe the position in the sky at that time.

Answer 1

Hint: The Indians philosophers and mathematicians are the most ancient society to analyse the sky and study about the different patterns they observe in the sky during the earth’s revolution around the sun. These gave many contributions to science. Religious holidays are determined by a lunisolar calendar that is based on calculations of the actual positions of the Sun and Moon.

Complete answer:
The Indian calendars are completely based on the positions of different stars in the sky during a time with respect to the sun or the moon. There are two types of calendars – one based on the solar calendar and the other based on the lunar calendars. Now, a lunisolar method is being adopted, in which the position of the sun and the moon is taken collectively. This calendar determines the religious holidays in the country.
A solar month is calculated as the time taken by the sun to shift its apparent longitude 30 degrees, which is equivalent to the way we look for the zodiac changes. A solar month is defined as the interval required for the Sun’s apparent longitude to increase by 30 degrees, corresponding to the passage of the Sun through a zodiacal sign (rasi). The initial month of the year, Vaisakha, begins when the true longitude of the sun is ${23^ \circ }15'$ . Because the Earth’s orbit is elliptical, the lengths of the months vary from $29.2$ to $31.2$ days. The short months all occur in the second half of the year around the time of the Earth’s perihelion passage.
The lunar months are the time taken between two adjacent new moon days to occur. These are usually shorter than the solar months.
The names of the lunisolar months are as follows –
1. Caitra
2. Vaisakha
3. Jyaistha
4. Asadha
5. Sravana
6. Bhadra
7. Asvina
8. Karthika
9. Agrahayana
10. Pausa
11. Magha
12. Phalguna
These are also the names of the stars which are seen in the sky during a particular time of the year. The Indian calendar also has leap years that coincide with the Gregorian calendar.

Additional Information:
The history of calendars in India is a remarkably complex subject owing to the continuity of Indian civilization and to the diversity of cultural influences. In the mid-1950s, when the Calendar Reform Committee made its survey, there were about 30 calendars in use for setting religious festivals for Hindus, Buddhists, and Janis’s. Some of these were also used for civil dating. These calendars were based on common principles, though they had local characteristics determined by long-established customs and the astronomical practices of local calendar makers. In addition, Muslims in India used the Islamic calendar, and the Indian government used the Gregorian calendar for administrative purposes.

Note:
The Indian calendar is mainly based on the Hindu religion which gives much importance to the stars and their position in the sky with respect to the sun, the moon and the other planets in the solar system. Other religions have also adapted this calendar method.