02 May Hindu Calender
Mathematically, Hindu calendar is purely theory and zodiac based. Nothing is religious about it. Month name is purely based on the name of constellation where the moon is near at the time of Full moon.
The ancient Hindus used a complex calendar that used the sun and the moon in defining the day, month and year.
While days and months were defined by the moon, the year was defined by the sun. Regarding the Earth’s motion, Aryabhatta I suggested about one millennium before Copernicus a theory in which the Earth was in axial rotation.
All stars, but not planets, were at rest in this theory. Aryabhata I’s hypothesis of the Earth’s rotational motion is clearly explained by the analogy of a boatman who observes objects on the shore moving backward.
The various Hindu calendars are based on eras and epochs. Generally, the Hindu calendar follows the lunar year that consists of 12 lunar months. A lunar month has two fortnights.
Names of the 12 months of the Indian Civil Calendar and Correlation with Gregorian Calendar
Chaitra (30 / 31* Days) Begins March 22 / 21*
Vaisakha (31 Days) Begins April 21
Jyaistha (31 Days) Begins May 22
Asadha (31 Days) Begins June 22
Shravana (31 Days) Begins July 23
Bhadra (31 Days) Begins August 23
Asvina (30 Days) Begins September 23
Kartika (30 Days) Begins October 23
Agrahayana (30 Days) Begins November 22
Pausa (30 Days) Begins December 22
Magha (30 Days) Begins January 21
Phalguna (30 Days) Begins February 20* Leap years
Names of the 7 Days in the Hindu Week
Raviãra: Sunday (day of Sun)
Somavãra: Monday (day of Moon)
Mañgalvã: Tuesday (day of Mars)
Budhavãra: Wednesday (day of Mercury)
Guruvãra: Thursday (day of Jupiter)
Sukravãra: Friday (day of Venus)
Sanivãra: Saturday (day of Saturn)