sentences:  The length of Ayyám-i-Há varies according to the timing of the following vernal equinox so that the next year always starts on the vernal equinox.The 2020 dates for this observance are from sunset on Tuesday, February 25, to sunset on Saturday, February 29.The Báb, the founder of the Bábí Faith, instituted the Badíʻ calendar in the Persian Bayán with 19 months of 19 days each and a period of intercalary days to allow for the calendar to be solar.