On 10 July 2014, the Universal House of Justice announced the adoption of provisions for the common implementation of the Badí‘ calendar beginning at Naw-Rúz 172 (sunset 20 March 2015). The first day of the month of fasting now varies according to the day on which Naw-Rúz of the coming year falls.
In its message dated 10 July 2014 concerning the common implementation of the Badí‘ calendar beginning at Naw-Rúz 172, the Universal House of Justice designated Ṭihrán as the spot on the earth that would serve as the standard for determining, by means of astronomical computations from reliable sources, the moment of the vernal equinox in the northern hemisphere and thereby the day of Naw-Rúz.
In its message dated 10 July 2014 concerning the common implementation of the Badí‘ calendar, the Universal House of Justice stated that the Festivals of the Twin Birthdays are to be observed on the first and the second day following the occurrence of the eighth new moon after Naw-Rúz, as determined in advance by astronomical tables using Ṭihrán as the point of reference.
With the implementation of the Badí‘ calendar as announced by the Universal House of Justice in its message dated 10 July 2014, the number of intercalary days varies according to the timing of the vernal equinox in successive years.