Weekends that begin the next bid period are not considered.
In the example above, the period is May and ends on May 31st. The weekend of Saturday, June 1st to Sunday, June 2nd are not considered by this bid.
In the example above, the carry-out pairing does not violate the Prefer Off Weekend bid.
In order to guarantee all weekends off, you would have to enter a separate bid to cover the weekend after the end of the period. You could enter an Avoid Carry Outs bid or a Prefer Off specific days bid.