The Indian national calendar, called the Shaka calendar or Śaka calendar, is a solar calendar that is used alongside the Gregorian calendar by The Gazette of India, in news broadcasts by All India Radio, and in calendars and official communications issued by the Government of India. Śaka Samvat is generally 78 years behind the Gregorian Calendar, except from January to March, when it is behind by 79 years.
Mohar of Gorkha (later Nepal's) king Prithvi Narayan Shah, dated Shaka era 1685 (1763 CE).
Image: Surya graha
Image: Chandra graha
Image: Angraka graha
The Gregorian calendar is the calendar used in most parts of the world. It went into effect in October 1582 following the papal bull Inter gravissimas issued by Pope Gregory XIII, which introduced it as a modification of, and replacement for, the Julian calendar. The principal change was to space leap years differently so as to make the average calendar year 365.2425 days long, more closely approximating the 365.2422-day 'tropical' or 'solar' year that is determined by the Earth's revolution around the Sun.
Christopher Clavius (1538–1612), one of the main authors of the reform
Pope Gregory XIII, portrait by Lavinia Fontana, 16C
First page of the papal bull Inter gravissimas
Detail of the pope's tomb by Camillo Rusconi (completed 1723); Antonio Lilio is genuflecting before the pope, presenting his printed calendar.
