A few summer camps have a small dining room that can't fit all the campers and counselors for a meal at one time. Therefore, the camp schedules two meal shifts.
During the Nine Days, the camp schedules a siyum for, say, lunch so that they can eat meat. Can the person who makes the siyum for the first shift repeat the siyum on the same masechta for the second shift? Or is a siyum a "one shot deal"? Let's say no one else is available to make a siyum on a different (or same) masechta for the 2nd shift. Does that change anything?