Why do airlines charge less for a round-trip trip ticket if the traveler stays over a Saturday night?

为何如果旅客周六停留一晚，航空公司对往返机票的收费就要低？

youdao

Why do airlines charge less for a round-trip trip ticket if the traveler stays over a Saturday night?

为何如果旅客周六停留一晚，航空公司对往返机票的收费就要低？

youdao