Origin of Hindu calendar

Question

The Hindu calendar is based on the Lunisolar calendar. There are 12 months in it.

Month names of Lunisolar calendar:

• Chaitra
• Vaiśākha
• Jyeṣṭha
• Āṣhāḍha
• Śhrāvaṇa
• Bhādrapada
• Āśhvina
• Kārtika
• Mārgaśīrṣa
• Pauṣya
• Māgha
• Phālguna

My Questions:

• What is the origin of these names of Lunar month?

• What is the meaning of each one?

• Is Lunisolar calendar derived from any Veda?

• Who has given these names to each Lunar month?

• What is the difference between Adhika masa and Nija masa?

Answer 1

The Hindu calendar is not a lunar calendar but a Lunisolar calendar. The year is always calculated based on Sun. Some regional calendars calculate both month and the nakshatra based on Moon, where as some calculate even months based on Sun and only the nakshatra based on Moon. You can check the wiki link to get more details.