A survey of the Modification Process of the Official Solar Hijri Calendar of Iran in 1304/1925

The purpose of the present study is to investigate the modification process of the official Solar Hijri Calendar of Iran in 1925. Before the Constitutional Revolution in Iran, various calendars, such as the Hijri Lunar calendar, were used. Consequently numerous problems, including the implementation of calendars, and there were many differences in the calendars, many problems with the mobility of the AH calendar months in economic transactions. The method of this research is descriptive-analytical and is based on archival documents. Following the appropriate answer to the main question of this research, what were the context, goals, and process of reforming the Solar Hijri Calendar and how it happened? One of the grounds for this reform, the general calculation law was adopted by the National Assembly of the Second National Assembly and was used in the calculations of the Hijri calendar. In other areas the cultural activity of the Kaveh newspaper was very effective. Seyyed Hassan Taqizadeh wrote articles about the necessity of reforming the calendar and using the Solar Hijri Calendar, until the fifth parliamentary term, Taqizadeh, a member of the parliament, proposed the change of names formonths.This idea was approved on 31.March 1925.