Also known as Ayyam-i-Ha, Days of Há, Ayyámu'l-Há
Ayyám-i-Há is a period of intercalary days in the Baháʼí calendar, when Baháʼís celebrate the Festival of Ayyám-i-Há. The four or five days of this period are inserted between the last two months of the calendar (Mulk and ʻAláʼ). 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.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).