- The national calendar based on the Saka Era, with Chaitra as its first month and a normal year of 365 days was adopted from 22nd March, 1957 along with the Gregorian calendar for : (i) Gazette of India, (ii) news broadcast by All India Radio, (iii) calendars issued by the Government of India and (iv) Government communications addressed to the public.
- Dates of the national calendar have a permanent correspondence with dates of the Gregorian calendar, 1 Chaitra falling on 22 March normally and on 21 March in leap year.