In contrast, promotion from one dan to the next can take years. The general rule is that a black belt may advance from one rank to the next only after the number of years equivalent to their current rank. For example, a newly promoted third-degree black belt may not be allowed to advance to fourth-degree until three years have passed. Some organizations also have age requirements related to dan promotions, and may grant younger students poom 품 (junior black belt) ranks rather than dan ranks until they reach a certain age.