Beltane is a fertility festival celebrated throughout the Eastern Lands. One of the Great Holidays, Beltane occurs in late spring. Couples jump over the embers of fires to ask for fertility in the coming year--whether human fertility or to ensure a good harvest.
The festival is of some importance in Tamora Pierce's Tortall novels.
In the third century of the Human Era the festival was already a holiday on April 30. Then, couples not only jumped over embers but people also danced on the Common and were out late. Rebakah Cooper had duty that night in 246 HE. She and her partners saved a well-off couple from being robbed. Her fellow puppy Verene and her senior partner Rollo were killed that night.
Two centuries later Veralidaine Sarrasri was conceived in a Beltane night, when the god of the hunt, Weiryn, visited her mother. Because Beltane is a Great Holiday in the Eastern Lands not only Great Gods can pass between the Mortal Realms and the Divine Realms then but also Minor Gods like Weiryn or--after she died--Daine's mother, Sarra, once she became the Green Lady. Even King Jonathan and his wife Thayet honor the Beltane custom and jump over the embers every year.