Ascension of Bahá'u'lláh (Baháʼí Faith) (Only if Baháʼí Naw-Rúz falls on March 21 of the Gregorian calendar)

The Baháʼí calendar used in the Baháʼí Faith is a solar calendar consisting of nineteen months and four or five intercalary days, with new year at the moment of Northern spring equinox. Each month is named after a virtue, as are the days of the week. The first year is dated from 1844 CE, the year in which the Báb began teaching.

The Baháʼí Faith is a religion founded in the 19th century that teaches the essential worth of all religions and the unity of all people. Established by Baháʼu'lláh, it initially developed in Iran and parts of the Middle East, where it has faced ongoing persecution since its inception. The religion has 5–8 million adherents spread throughout most of the world's countries and territories.

Naw-Rúz is the first day of the Baháʼí calendar year, and one of eleven holy days for adherents of the Baháʼí Faith. It occurs on the northern vernal equinox, on or near March 21, which is also the traditional Persian New Year.

The Gregorian calendar is the calendar used in most parts of the world. It went into effect in October 1582 following the papal bull Inter gravissimas issued by Pope Gregory XIII, which introduced it as a modification of, and replacement for, the Julian calendar. The principal change was to space leap years slightly differently to make the average calendar year 365.2425 days long rather than the Julian calendar's 365.25 days, thus more closely approximating the 365.2422-day "tropical" or "solar" year that is determined by the Earth's revolution around the Sun.