The Bahá'í Faith has a unique calendar of 19 months of 19 days each, plus 4 or 5 days of Ayyam-i-Ha to bring the length of the year up to a full solar cycle. Through this calendar, “sacred moments are distinguished, humanity’s place in time and space are reimagined, and the rhythm of life recast.” The Universal House of Justice, in a letter dated July 10, 2014, has called “upon the Bahá'ís of the East and West to adopt . . . the provisions that will unite them in the common implementation of the Badi‘ calendar.” The House of Justice has also fixed the start of the year on the first day of spring as it occurs in Tehran. In The Badi‘ (Bahá'í) Calendar we will consider the purpose and nature of calendars in general, the organization of the Bahá'í calendar (created by the Báb and called the Badi‘ calendar), the spiritual significance of the names of “the periods and cycles, months and days” in the calendar, and the purpose and timing of Bahá'í holy days. We will also compare the Bahá'í calendar to the Jewish, Christian, and Islamic calendars.