根据下面资料，回答题
In period of the summer holidays there will be a revised schedule( 修改过的时刻表)of ser-vices for the students. Changes for dining-room and library service hours and for bus schedules will be posted on the wall outside the dining-hall. Weekly film and concert schedules, which are being arranged( 安排), will be posted each Wednesday outside the student club.
During the summer holidays, buses going to the town centre will leave the main hall every hour on the half hour during the day. The dining-room will serve three meals a day from 7:00 a. m.to 7:00 p.m. during the week and two meals from noon to 7:00 p.m. on weekends. The library will continue its usual hours during the week, but has shorter hours on Saturdays and Sundays. The weekend hours are from noon to 5:00 p. m.
All students who want to use the library lending services must have a new summer card. This announcement will also appear in the next week´s student newspaper.
The main purpose of this text is to__________．