The Bahá'í calendar, formally known as the Badí' Calendar, was devised by the Báb and completed by Bahá'ulláh. Being a solar calendar, the Bahá'í calendar begins on March 21, the first day of spring. Holy days, Anniversaries and Feast Days are observed and celebrated throughout the year.

The Bahá'í year consists of 19 months of 19 days each (i.e., 361 days), with the addition of certain 'intercalary days' (four in ordinary and five in leap years) between the eighteenth and nineteenth months in order to adjust the calendar to the solar year. The Báb named the months [as well as the days of the week and several of the years comprising a cycle] after the attributes of God. The Bahá'í New Year, like the ancient Persian New Year, is astronomically fixed, commencing at the March equinox (21 March), and the Bahá'í era commences with the year of the Báb's declaration (i.e. 1844 A.D., 1260 A.H.).

The days of the week are as follows:

Days	Arabic Name	Translation	English Name
1st	Jalál	Glory	Saturday
2nd	Jamál	Beauty	Sunday
3rd	Kamál	Perfection	Monday
4th	Fidál	Grace	Tuesday
5th	'Idál	Justice	Wednesday
6th	Istijlál	Majesty	Thursday
7th	Istiqlál	Independence	Friday

Bahá'u'lláh designated...[the intercalary days]...as the Ayyám-i-Há and ordained that they should immediately precede the month of 'Alá', which is the month of fasting. He enjoined upon His followers to devote these days to feasting, rejoicing, and charity. Immediately upon the termination of these intercalary days, Bahá'u'lláh ordained the month of fasting to begin...The Báb has, moreover, in His Writings...divided the years following the date of His Revelation in cycles of nineteen years each...Each cycle of nineteen years is called Váhid. Nineteen cycles constitute a period called Kull-i-Shay'. The numerical value of the word Váhid is nineteen, that of Kull-i-Shay' is 361. Váhid signifies unity, and is symbolic of the unity of God...The names of the years in...[a cycle]...are as follows:

Years	Arabic Name	Translation
1st	Alif	A.
2nd	Bá'	B
3rd	Ab	Father
4th	Dál	D.
5th	Báb	Gate
6th	Váv	V.
7th	Abad	Eternity
8th	Jád	Generosity
9th	Bahá	Splendour
10th	Hubb	Love
11th	Bahháj	Delightful
12th	Javáb	Answer
13th	Ahad	Single
14th	Vahháb	Bountiful
15th	Vidád	Affection
16th	Badí'	Beginning
17th	Bahí	Luminous
18th	Abhá	Most Luminous
19th	Váhid	Unity