The Nineteen-Day Fast occupies the final month of the Badi calendar, the nineteen-month, nineteen-day calendar Baha'u'llah instituted and named for attributes of God; each month bears one of those names, and the fasting month, Ala, means loftiness or exaltation. Because the calendar is fixed to the solar year and anchored to the vernal equinox, the fast runs from 2 to 20 March in the Gregorian calendar in ordinary years, a period that in the northern hemisphere overlaps only roughly with the Islamic month of Ramadan, since the Badi calendar is solar and Ramadan follows a lunar one.
The fast ends precisely at the vernal equinox, which the Badi calendar treats as New Year's Day, Naw-Ruz, one of the faith's nine holy days on which work is suspended. The sequence built into the calendar, three weeks of daytime fasting immediately followed by a festival celebrating the turn of the year, gives the fast a structural role distinct from Ramadan's month of nightly feasting or the penitential logic of a Christian Lent: it functions as a period of spiritual stock-taking that closes exactly as the new Baha'i year opens, a design Shoghi Effendi's writings describe as intentional, meant to carry worshippers from self-examination directly into renewal.