Depends. If the bid is for the same center, the person with the higher p/t seniority should work first and get the better seniority for friend/t. If they start in different centers, it is whoever has their 30 days in first depending on their first day of the 30. The first day worked is usually the seniority date. My question would be why you, as the less senior person, went to school earlier than the senior person?