2,073. The Differences Between a Major and a Minor Zavah

Hilchos Issurei Biah 6:8

There’s no difference between a major and a minor zavah except for counting seven days and the obligation to bring an offering. A major zavah must count seven “clean” days, while a minor zavah need only count one day; a major zavah must bring an offering when she purifies herself, while a minor zavah need not. Both are ritually unclean and the prohibition against intimacy applies to both of them.

Hilchos Issurei Biah 6:9

Accordingly, if a woman found blood in her days of zivah, whether at the beginning of the night or the end of the day, she is ritually unclean that whole day as if she didn’t stop bleeding from the time she saw the blood until the sun went down. The woman must watch herself overnight and, if there aren’t any signs of bleeding overnight, she should get up in the morning and immerse in a mikvah after sunrise. She must then watch herself throughout the day. If there aren’t any signs of bleeding by day, then it is a clean day corresponding the unclean day and she is permitted to her husband that night.