How the Badí’ calendar works
The Badí’ calendar has 19 months of 19 days each, 361 days, plus four or five intercalary days called Ayyám-i-Há, which come before the last month, ‘Alá’, the month of the Fast. The months are named after attributes of God, such as Bahá (Splendour), Jalál (Glory) and ‘Ilm (Knowledge). Years are counted from 1844, so 183 B.E. (Bahá’í Era) runs from March 2026 to March 2027. Each day begins at sunset, so a Holy Day starts on the evening before the Gregorian date it is listed under.
When Naw-Rúz and the Twin Holy Birthdays fall
Since 172 B.E. (2015) the calendar has been used in the same way worldwide, following a decision of the Universal House of Justice. Naw-Rúz, the new year, falls on the day of the March equinox, with Tehran as the reference point: if the equinox comes before sunset in Tehran, that day is Naw-Rúz; otherwise the next day is. So Naw-Rúz can be on 20 or 21 March. The Birth of the Báb and the Birth of Bahá’u’lláh, together called the Twin Holy Birthdays, fall on the first and second days after the eighth new moon after Naw-Rúz, so they move between mid-October and mid-November. The other Holy Days keep fixed dates in the Badí’ calendar.
How this converter calculates, and how it was checked
The tool finds the moment of the March equinox with Jean Meeus’s astronomical algorithms, the new moons with Meeus’s lunar phase method, and the time of sunset in Tehran with the same solar code as our prayer times. We then compared every year from 172 to 221 B.E. with the official table of dates published on bahai.org, and all 50 years match. In one year, 2026, the equinox fell less than a minute from sunset in Tehran, too close for any formula to settle, so for that year the tool uses the date published by the Bahá’í World Centre, 21 March. Years outside the published table are not offered.
Holy Days and other dates in the year overview
For each year the overview lists the nine Holy Days: Naw-Rúz, the First, Ninth and Twelfth Days of Riḍván, the Declaration of the Báb, the Ascension of Bahá’u’lláh, the Martyrdom of the Báb, the Birth of the Báb and the Birth of Bahá’u’lláh. It also lists the Day of the Covenant and the Ascension of ‘Abdu’l-Bahá, the first day of each month, the days of Ayyám-i-Há and the 19 days of the Fast. Local communities announce their own gatherings for these days, so check with your local community for times and places.
What this converter is, and is not
This is a general calendar tool. It is not religious guidance and does not replace the calendar published by the Bahá’í World Centre or the dates your local community announces. It covers only 172 to 221 B.E. (2015 to 2065), the years in the official table. Earlier and later years are not converted, because the tool’s results are checked only against that official table.