<P> The historic Shalivahana era calendar is still widely used . It has years that are solar sidereal (after periodic adjustments), and has lunar months . The official Saka uses a tropical solar year . </P> <P> The calendar months follow the signs of the tropical zodiac rather than the sidereal zodiac normally used with the Hindu calendar . </P> <Table> <Tr> <Td> #</Td> <Th> Month (Sanskrit) </Th> <Th> Length </Th> <Th> Start date (Gregorian) </Th> <Th> Tropical zodiac </Th> <Th> Tropical zodiac (Sanskrit) </Th> </Tr> <Tr> <Td> </Td> <Td> Chaitra </Td> <Td> 30 / 31 </Td> <Td> March 22 / 21 </Td> <Td> Aries </Td> <Td> Meṣa </Td> </Tr> <Tr> <Td> </Td> <Td> Vaishākha </Td> <Td> 31 </Td> <Td> April 21 </Td> <Td> Taurus </Td> <Td> Vṛṣabha </Td> </Tr> <Tr> <Td> </Td> <Td> Jyēshtha </Td> <Td> 31 </Td> <Td> May 22 </Td> <Td> Gemini </Td> <Td> Mithuna </Td> </Tr> <Tr> <Td> </Td> <Td> Āshādha </Td> <Td> 31 </Td> <Td> June 22 </Td> <Td> Cancer </Td> <Td> Karkata </Td> </Tr> <Tr> <Td> 5 </Td> <Td> Shrāvana </Td> <Td> 31 </Td> <Td> July 23 </Td> <Td> Leo </Td> <Td> simha </Td> </Tr> <Tr> <Td> 6 </Td> <Td> Bhaadra </Td> <Td> 31 </Td> <Td> August 23 </Td> <Td> Virgo </Td> <Td> Kanyā </Td> </Tr> <Tr> <Td> 7 </Td> <Td> Āshwin </Td> <Td> 30 </Td> <Td> September 23 </Td> <Td> Libra </Td> <Td> Tulā </Td> </Tr> <Tr> <Td> 8 </Td> <Td> Kārtika </Td> <Td> 30 </Td> <Td> October 23 </Td> <Td> Scorpio </Td> <Td> Vṛścik‌‌‌a </Td> </Tr> <Tr> <Td> 9 </Td> <Td> Agrahayana </Td> <Td> 30 </Td> <Td> November 22 </Td> <Td> Sagitarius </Td> <Td> Dhanur </Td> </Tr> <Tr> <Td> 10 </Td> <Td> Pausha </Td> <Td> 30 </Td> <Td> December 22 </Td> <Td> Capricorn </Td> <Td> Makara </Td> </Tr> <Tr> <Td> 11 </Td> <Td> Māgha </Td> <Td> 30 </Td> <Td> January 21 </Td> <Td> Aquarius </Td> <Td> Kumbha </Td> </Tr> <Tr> <Td> 12 </Td> <Td> Phalguna </Td> <Td> 30 </Td> <Td> February 20 </Td> <Td> Pisces </Td> <Td> Mīna </Td> </Tr> </Table> <Tr> <Td> #</Td> <Th> Month (Sanskrit) </Th> <Th> Length </Th> <Th> Start date (Gregorian) </Th> <Th> Tropical zodiac </Th> <Th> Tropical zodiac (Sanskrit) </Th> </Tr>

Which is the first month of the national calender of india