The Báb introduced a new calendar, known now as the Badi' or
Bahá'í calendar … According to this calendar, a day is the period from sunset
to sunset. In the Bayan, the Báb ordained the month of Ala' to be the month of
fasting, decreed that the day of Naw-Ruz should mark the termination of that
period, and designated Naw-Ruz as the Day of God. Bahá'u'lláh confirms the
Badi' calendar wherein Naw-Ruz is designated as a feast. Naw-Ruz is the first
day of the new year. It coincides with the spring equinox in the northern
hemisphere, which usually occurs on 21 March. Bahá'u'lláh explains that this
feast day is to be celebrated on whatever day the sun passes into the
constellation of Aries (i.e. the vernal equinox), even should this occur one
minute before sunset (Q and A 35). Hence Naw-Ruz could fall on 20, 21, or 22
March, depending on the time of the equinox. Bahá'u'lláh has left the details of
many laws to be filled in by the Universal House of Justice. Among these are a
number of matters affecting the Bahá'í calendar. The Guardian has stated that
the implementation, worldwide, of the law concerning the timing of Naw-Ruz will
require the choice of a particular spot on earth which will serve as the
standard for the fixing of the time of the spring equinox. He also indicated
that the choice of this spot has been left to the decision of the Universal
House of Justice.
(The Universal House of Justice, ‘Notes’ section of ‘The
Kitab-i-Aqdas’)
