The Journal of the Anthropological Society of Bombay March 1952

As the days of the month in the inscriptions are exactly the same in the Persian and the Babylonian versions it has been concluded that the calendar used by Dariush was the Babylonian calendar in which the only change was that the Semitic names of the months were replaced by Persian names. [...] As the five extra days were inserted in Calendar A after Spentarmad but were not so inserted in Calendar C. the 1st Gatha day of Calendar A was the 1st day of Farvardin of Calendar C and the 1st day of Farvardin of Calendar A was the 6th day Khordad of the month Farvardin of Calendar C. The latter has for long been celebrated as the Khordad Sal and used to be referred to as the greater Nawroz; th [...] Very similar is the explanation of the apparent anomaly in the statement of the Irani Bun--dahhishn which identifies the season of Maidhyo--shem and the month of Tir of Calendar B with the month of Shahrevar and the month of Spentarmad of Calendar B in the season of Hama--spath--maedem with the month of Farvardin. [...] When Tir of Calendar B coincided with the month Shahrevar of Calendar A the month of Deh of Calendar B would agree with the month of Spentarmad of Calendar A: but as the five extra days would be inserted in Calendar A after the latter the 6th day of Bahman of Calendar B would be the 1st day of Farvardin of Calendar A and therefore the 1st day of Spentarmad of Clendar B would be the 26th day o [...] There is however definiteTHE DEVELOPMENT OF THE IRANIAN CALENDARS 31 information that the calendar was re--adjusted once again in the year 1606-1007 A C. THE KADMI CALENDAR At that period the month of Farvardin of Calendars A & C came in the spring; Firdausi and other writers of the time refer to the month of Farvardin ushering in the spring.