Birkat Hachama is observed by Judaists and Jews which only occurs every 28 years solar cycle known as "Machzor Gadol" (מחזור גדול, "the great cycle").
Birkat Hachama is observed by Judaists and Jews which only occurs every 28 years solar cycle known as "Machzor Gadol" (מחזור גדול, "the great cycle").