In February 1979, Ayatollah Ruhollah Khomeini returned to Iran after 15 years in exile and led the campaign to overthrow the Shah of Iran.

Two months later, the new government held a referendum on establishing the Islamic Republic based on a new constitution replacing the Persian monarchy that had ruled for 2,500 years.

On 12 Farvardin, the results of the referendum were  announced with 98.2% of the Iranian people voting in favour of an Islamic Republic

The month of Farvardin is determined by the vernal equinox. If the equinox falls on March 21st, Farvardin 12 is on April 1st.

This public holiday is followed by another public holiday on Farvardin 13. Sidzeh Bedar (also known as Nature Day) marks the culmination of the festivities for Nowruz, Persian New Year.