# Nirayana

By Swami Harshananda

nirayana (‘neglecting the precession of the equinoxes’)

An equinox is the point where the sun crosses the plane of the earth’s equator. There are two equinoxes: the vernal equinox (on March 21) and the autumnal equinox (on September 22). On

these two days, the length or the duration of the day and the night are exactly equal.

In the traditional Hindu calendars (called ‘paṅcāṅgas’) the precession of the equinoxes (due to the wobbling movement of the earth) is not taken into account. Hence this system of calculation is known as nirayana whereas, if taken into account, it is called sāyana.

Though the actual date of the vernal equinox at present is 21st March, it is considered as 13th April ignoring the precession.

In order to remove this anomaly, the National Calendar (as recommended by the Calendar Reform Committee) was adopted in 1957. March 22 was reckoned as the 1st Caitra, Śaka-era 1879. The duration of the year adopted for calculations taking the ayana or precession into account (hence ‘sāyana’) was 365.2422 days.

## References

• The Concise Encyclopedia of Hinduism, Swami Harshananda, Ram Krishna Math, Bangalore

## OLD CONTENT

nirayana (‘neglecting the precession of the equinoxes’) An equinox is the point where the sun crosses the plane of the earth’s equator. There are two equinoxes: the vernal equinox (on March 21) and the autumnal equinox (on September 22). On these two days, the length or the duration of the day and the night are exactly equal. In the traditional Hindu calendars (called ‘pañcāṅgas’) the precession of the equinoxes (due to the wobbling movement of the earth) is not taken into account. Hence this system of calculation is known as nirayana whereas, if taken into account, it is called sāyana. Though the actual date of the vernal equinox at present is 21st March, it is considered as 13th April ignoring the precession. In order to remove this anomaly, the National Calendar (as recommended by the Calendar Reform Committee) was adopted in 1957. March 22 was reckoned as the 1st Caitra, Śaka-era 1879. The duration of the year adopted for calcula¬tions taking the ayana or precession into account (hence ‘sāyana’) was 365.2422 days.