Demographics
Main article: Demographics of Iran
Almost two-thirds of Iran's people are of Aryan origin and speak one of the Indo-Iranian languages, though only Persian (Farsi), which is written in the Arabic alphabet, is an official language. The major groups in this category include Persians (51%), Gilaki and Mazandarani (8%), Kurds (7%), Lurs (2%), and Baluchi (2%). The remainder are primarily Turkic people such as the Azeri (24%) and Turkmen (2%), but also include Arabs (3%), Armenians, Jews, and Assyrians and others. Arabic, being the language of the Qur'an, is taught in schools as well.
Most Iranians are Muslims; 89% belong to the Shiite branch of Islam, the official state religion, and about 10% belong to the Sunni branch, which predominates in most Muslim countries. Non-Muslim religious minorities include Baha'is and Zoroastrians, both being religions that originated in Iran, as well as Jews and Christians. Only the latter three are officially recognised minority religions. Iran's population size increased dramatically in the latter part of the 20th century.
Culture
Main article: Culture of Iran
Holidays
Iran uses three official calendar systems. The solar Islamic calendar as the main date, the lunar Islamic calendar for religious events, and the Gregorian calendar for international events (like the May Day).