The Bahá'í calendar, also called the Badí‘ calendar (badí‘ means wondrous or unique ), used by Bábism and the Bahá'í Faith, is a solar calendar with regular years of 365 days, and leap years of 366 days. Years are composed of 19 months of 19 days each, (361 days) plus an extra period of "Intercalary Days" (4 in regular and 5 in leap years). Years in the calendar begin at the vernal equinox, and are counted with the date notation of BE (Bahá'í Era), with 21 March 1844 CE being the first day of the first year, the year the Báb proclaimed his religion. The period from 21 March 2014 to 20 March 2015 is the year 171 BE. At present, the Bahá'í calendar is synchronized to the Gregorian calendar, meaning that the extra day of a leap year occurs simultaneously in both calendars. The Badi calendar was implemented during the Bábí faith and then adapted in the Bahá'í Faith.
The Bahá'í scriptures left a number of issues regarding the implementation of the Badi calendar to be resolved by the Universal House of Justice before the calendar can be observed uniformly worldwide. On 10 July 2014 the Universal House of Justice announced provisions that will enable the common implementation of the Badi calendar worldwide, beginning at sunset 20 March 2015. For instance, beginning in March 2015 the Badi calendar will no longer be locked to the Gregorian calendar, nor will the Twin Festivals, the Births of the Báb and Bahá'u'lláh, be any longer observed according to the lunar Islamic calendar, as they have been in some eastern countries until now. These changes will come into effect beginning 20 March 2015, or Bahá 1 in the year 172 BE. 
The Bahá'í calendar started from the original Badí‘ calendar, created by the Báb in the Persian Bayán (5:3) and the Kitab-i-Asmá. An early version of the calendar began to be implemented during his time. It used a scheme of 19 months of 19 days (19x19) for 361 days, plus intercalary days to make the calendar a solar calendar. The first day of the early implementation of the calendar year was Nowruz, while the intercalary days were assigned differently than the later Bahá'í implementation. The calendar contained symbolic connections to prophecies of the Báb about the next Manifestation of God termed He whom God shall make manifest.
Bahá'u'lláh, the founder of the Bahá'í Faith, who claimed to be the one prophesied by the Báb, confirmed and adopted this calendar and made Naw-Rúz the first day of the year, and also clarified the position of the intercalary days, as 4 or 5 days before the last month. Bahá'u'lláh set Naw-Rúz to the day on which the sun passes into the constellation Aries. Bahá'ís interpret this formula as a specification of the vernal equinox. Although the vernal equinox can occur on March 20, 21 or 22, Shoghi Effendi declared that, for the time being, the Badí‘ calendar was to be 'locked' to the Gregorian calendar with the new year always starting at sunset on 20 March.
In 2014, the Universal House of Justice selected Teheran, the birthplace of Bahá'u'lláh, as the location to which the date of the vernal equinox is to be fixed, thereby "unlocking" the Badí' calendar from the Gregorian calendar. In the same message the Universal House of Justice decided that the birthdays of the Báb and Bahá'u'lláh will be celebrated on "the first and the second day following the occurrence of the eighth new moon after Naw-Rúz"  and fixed the dates of the Bahá'í Holy Days on the Badí' calendar. These changes will come into effect as of 20 March 2015 (sundown).
Years in the Bahá'í calendar are counted from Thursday, 21 March 1844, the beginning of the Bahá'í Era or Badí‘ Era (abbreviated BE or B.E.). Year 1 BE thus began at sundown 20 March 1844. Using the Bahá'í names for the weekday and month, day one of the Bahá'í Era was Istijlál (Majesty), 1 Bahá (Splendour) 1 BE. As detailed below, the names of the Bahá'í months and days reflect attributes of God. William Miller's polemical work against the Bahá'í Faith claims that the date the calendar was to begin was 1850 CE though most sources agree the date was with the Declaration of the Bab to Mullá Husayn, May 23, 1844 CE.
The Bahá'í calendar is composed of 19 months, each with 19 days. The Nineteen Day Fast is held during the final month of ‘Alá’ (2 March – 20 March), and is preceded by the intercalary days, known as Ayyám-i-Há. There are four intercalary days in a regular year, and five in a leap year. The introduction of intercalation marked an important break from Islam, as under the Islamic calendar the practice of intercalation had been specifically prohibited in the Qur'an. The month of fasting is followed by Naw-Rúz, the new year. Because the calendar is currently synchronized with the Gregorian calendar, the Bahá'í leap years happen on common era leap years. In addition, the intercalary days include 28 February and 1 March, causing precise synchronization of the 19 months with the Gregorian calendar.
The names of the months were taken by the Báb from the Du'ay-i-Sahar, a Ramadan dawn prayer by Imam Muhammad al-Baqir, the fifth Imam of Twelver Shi'ah Islam. These month names are described as describing attributes of God.
In the Persian Bayan the Báb divides the months in four groups, of three, four, six and six months respectively. Robin Mirshahi suggests a possible link with four realms described in Bahá'í cosmology.
Note the days of the month have the same names as the names of the month - the 9th day of the month for example is the same as the 9th month - Asmá, or "Names". In the following table, the Gregorian date indicates the first full day of the month. The month begins at sunset of the Gregorian date previous to the one listed, after which time that month's Nineteen Day Feast may be celebrated.
(if Naw-Rúz falls on 21 March) 
|Arabic name ||Arabic script||English name ||Additional meanings in authorized English translations of Bahá'í scripture |
– 8 April
|Bahá||بهاء||Splendour||glory, light, excellence|
– 27 April
– 16 May
– 4 June
|‘Aẓamat||عظمة||Grandeur||glory, majesty, dominion, greatness|
– 23 June
|Núr||نور||Light||radiance, brightness, splendour, effulgence, illumination|
– 12 July
|Raḥmat||رحمة||Mercy||blessing, grace, favour, loving kindness, providence, compassion|
– 31 July
|Kalimát||كلمات||Words||utterance, the word of God|
– 19 August
|Kamál||كمال||Perfection||excellence, fullness, consummation, maturity|
– 7 September
|Asmá’||اسماء||Names||titles, attributes, designations|
– 26 September
|‘Izzat||عزة||Might||glory, power, exaltation, honour, majesty, grandeur, strength, sovereignty, magnificence|
– 15 October
|Mashíyyat||مشية||Will||purpose, the primal will, the will of God|
– 3 November
|‘Ilm||علم||Knowledge||wisdom, divine knowledge, revelation|
– 22 November
|Qudrat||قدرة||Power||might, authority, dominion, celestial might, omnipotence, transcendent power, indomitable strength, all-pervading power, ascendancy, divine power|
– 11 December
– 30 December
|Masá’il||مسائل||Questions||principles, truths, matters, mysteries, subtleties, obscurities, intricacies, problems|
– 18 January
– 6 February
|Sulṭán||سلطان||Sovereignty||king, lord, majesty, sovereign, monarch, authority, potency, the power of sovereignty, the all-possessing, the most potent of rulers|
– 25 February
|Mulk||ملك||Dominion||sovereignty, kingdom, realm, universe|
– 1 March
|Ayyám-i-Há||ايام الهاء||The Days of Há|
– 20 March
(Month of fasting)
The Bahá'í week starts on Saturday, and ends on Friday. Like Judaism and Islam, days begin at sunset on the previous solar day and end at sunset of the present solar day. Bahá'í writings indicate that Friday is to be kept as a day of rest. The practice of keeping Friday as a day of rest is currently not observed in all countries; for example, in the UK, the National Spiritual Assembly of the Bahá’ís confirmed it does not currently keep this practice.
|Arabic Name||Arabic Script||English Translation||Day of the Week|
There are eleven holy days in the Bahá'í calendar; on nine of these holy days, work is suspended. The Festival of Ridván, a twelve day festival that commemorates Bahá'u'lláh's announcement of prophethood, is the most holy Bahá'í festival and is referred to as the "Most Great Festival."
On the Islamic lunar calendar, the births of the Báb and Bahá'u'lláh fall on consecutive days; the first and second day of Muharram, respectively. The Universal House of Justice has decided to celebrate them on the first and second day following the eighth new moon after Naw-Rúz, from March 20, 2015 onwards.
|Name||Gregorian Dates||Work Suspended|
|Naw-Rúz (Bahá'í New Year)||March 21||Yes|
|First day of Riḍván (Arabic: رضوان)||April 21||Yes|
|Ninth day of Riḍván||April 29||Yes|
|Twelfth day of Riḍván||May 2||Yes|
|Declaration of the Báb||May 23||Yes|
|Ascension of Bahá'u'lláh||May 29||Yes|
|Martyrdom of the Báb||July 9||Yes|
|Birth of the Báb||October 20||Yes|
|Birth of Bahá'u'lláh||November 12||Yes|
|Day of the Covenant||November 26||No|
|Ascension of `Abdu'l-Bahá||November 28||No|
|Name||Dates on the Badí‘ Calendar ||Number of Days after Naw-Rúz||Dates on the Gregorian Calendar if Naw-Rúz falls on March 21||Work Suspended|
|Naw-Rúz (Bahá'í New Year)||Bahá 1||March 21||Yes|
|First day of Riḍván (Arabic: رضوان)||Jalál 13||31||April 21||Yes|
|Ninth day of Riḍván||Jamál 2||39||April 29||Yes|
|Twelfth day of Riḍván||Jamál 5||42||May 2||Yes|
|Declaration of the Báb||‘Aẓamat 8||64||May 24||Yes|
|Ascension of Bahá'u'lláh||‘Aẓamat 13||69||May 29||Yes|
|Martyrdom of the Báb||Raḥmat 17||111||July 10||Yes|
|Birth of the Báb||Celebrated on the first day after the eighth new moon following Naw-Rúz||Yes|
|Birth of Bahá'u'lláh||Celebrated on the second day after the eighth new moon following Naw-Rúz||Yes|
|Day of the Covenant||Qawl 4||250||November 26||No|
|Ascension of `Abdu'l-Bahá||Qawl 6||252||November 28||No|
Also existing in the Bahá'í calendar system is a 19-year cycle called Váḥid and a 361-year (19x19) supercycle called Kull-i-Shay’ (literally, "All Things"). Each of the 19 years in a Vahid has been given a name as shown in the table below. The 9th Váḥid of the 1st Kull-i-Shay’ started on 21 March 1996, and the 10th Váḥid will begin in 2015. The current Bahá'í year, year 171 BE (21 March 2014 - 20 March 2015), is year Váḥid (Unity) of the 9th Váḥid of the 1st Kull-i-Shay’. The 2nd Kull-i-Shay’ will begin in 2205.
The concept of a 19-year cycle has existed in some form since the 4th century BC. The Metonic cycle represents an invented measure that approximately correlates solar and lunar markings of time and which appears in several calendar systems.
- Years in a Váḥid
|No.||Persian Name||Arabic Script||English Translation|
- Buck, Christopher and Melton, J. Gordon (2011). “Bahā’ī Calendar and Rhythms of Worship.” Religious Celebrations: An Encyclopedia of Holidays, Festivals, Solemn Observances, and Spiritual Commemorations. By J. Gordon Melton, with James A. Beverley, Christopher Buck, and Constance A. Jones. Santa Barbara, CA: ABC-CLIO. (1:79–86.).
- Smith, Peter (2000). "calendar". A concise encyclopedia of the Bahá'í Faith. Oxford: Oneworld Publications. pp. 98–100. ISBN 1-85168-184-1.
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- Purushotma, Shastri Baha'is to Implement New Calendar Worldwide. Huffington Post. 14-07-2014.
- Taylor, John (2000-09-01). "On Novelty in Ayyám-i-Há and the Badí Calendar". bahai-library.org. Retrieved 2006-09-24.
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- Mihrshahi, Robin (2004) . "Symbolism in the Badi‘ Calendar". Baha'i Studies Review 12 (1). doi:10.1386/bsre.12.1.15. ISSN 1354-8697. Retrieved 5–1–2012. Check date values in:
- Universal House of Justice (1992). Notes of the Kitáb-i-Aqdas. Wilmette, Illinois, USA: Bahá'í Publishing Trust. pp. 178–179. ISBN 0-85398-999-0..
- Effendi, Shoghi (1973). Directives from the Guardian. India/Hawaii: Bahá'í publishing trust. p. 30.
- Curtis, Larry (2004-03-06). "A Day in the Bahá'í Calendar". bcca.org. Archived from the original on 2 October 2006. Retrieved 2006-09-24.
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- Bayat, Mangol (2000). Mysticism and Dissent: Socioreligious Thought in Qajar Iran. Modern Intellectual and Political History of the Middle East (reprint ed.). Syracuse University Press. p. 88. ISBN 978-0-8156-2853-8.
- Smith, Peter (2000). "Ayyám-i-Há". A concise encyclopedia of the Bahá'í Faith. Oxford: Oneworld Publications. p. 53. ISBN 1-85168-184-1.
- Taherzadeh, A. (1976). The Revelation of Bahá'u'lláh, Volume 1: Baghdad 1853-63. Oxford, UK: George Ronald. pp. 116–7. ISBN 0-85398-270-8.
- Stephen N. Lambden. The Du'á Sahar or Supplication of Glory-Beauty (al-bahá')
- Mihrshahi, Robin (2013). A Wondrous New Day: The Numerology of Creation and 'All Things' in the Badí' Calendar.
- Effendi, Shoghi (1950). The Bahá'í Faith: 1844-1950. Wilmette, Illinois: Bahá'í Publishing Committee.
- "Letter written on behalf of the Guardian to an individual believer". Bahá'í News (162, April 1943): 5. 1939-07-10. In Effendi, Shoghi; Bahá'u'llah, 'Abdu'l-Bahá, The Universal House of Justice (1983). Hornby, Helen, ed. Lights of Guidance: A Bahá'í Reference File. New Delhi, India: Bahá'í Publishing Trust. p. 109. ISBN 978-81-85091-46-4. Retrieved 2009-03-15. "III. Bahá'í: E. Miscellaneous Subjects: 372. Friday is Day of Rest in Bahá'í Calendar."
- Bellenir, Karen (2004). Religious Holidays and Calendars: An Encyclopedic Handbook (3rd ed.). Omnigraphics. p. 154. ISBN 0-7808-0665-4.
- National Spiritual Assembly of the Bahá’ís of the United Kingdom. Letter from the NSA to the Bahá’í Council for Wales Retrieved July 11, 2014.
- National Spiritual Assembly of the United States (2006-03-05). "The Badi Calendar". bahai.us. Archived from the original on 28 September 2006. Retrieved 2006-09-23.
- Walbridge, John (2003-10-02). "Ridvan". Retrieved 2006-09-23.
- Taherzadeh, Adib (1987). The Revelation of Bahá'u'lláh, Volume 4: Mazra'ih & Bahji 1877-92. Oxford, UK: George Ronald. p. 334. ISBN 0-85398-270-8.
- Smith, Peter (2000). "holy days". A concise encyclopedia of the Bahá'í Faith. Oxford: Oneworld Publications. pp. 182–183. ISBN 1-85168-184-1.
- Bolhuis, Arjen (2006-03-23). "The first Kull-i-Shay' of the Bahá'í Era". Retrieved 2006-09-23.
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- Mihrshahi, Robin (2013). A Wondrous New Day: The Numerology of Creation and 'All Things' in the Badí' Calendar.
- Significant Bahá’í Dates 172 B.E. (2015–2016)
- The Bahá'í Calendar
- Arithmetic of the Bahá'í Calendar, and Variants
- Bahá'í Calendar, Bahá'í Events and Holy Days (types: Persian, Islamic, Gregorian)