'Twenty year' in the Bible

Of the sons of Issachar, in their pedigrees - by their families by their ancestral houses, - in the counting of names, from twenty year old and upwards, every one able to go forth to war;

In the fifty-second year of Azariah king of Judah, Pekah the son of Remaliah became king over Israel, and reigned twenty years in Samaria.

These are the children of Levi in the households of their fathers the ancient heads, viewed and numbered by name and poll by poll from twenty year and above, to work in the service of the house of the LORD.