The days of their vow that were completed before their defilement no longer count. They must rededicate themselves to the Lord as a Nazirite for the full term of their vow, and each must bring a one-year-old male lamb for a guilt offering.
So Paul went to the Temple the next day with the other men. They had already started the purification ritual, so he publicly announced the date when their vows would end and sacrifices would be offered for each of them.