'Months' in the Bible

After that time, Elisabeth, being certain that she was to become a mother, kept herself from men's eyes for five months, saying,

And Mary was with her for about three months and then went back to her house.

Truly I say to you, There were a number of widows in Israel in the days of Elijah, when the heaven was shut up for three years and six months and there was no food in the land;