September 1. According to the information of Jiangsu Education Network, in 2023, the summer vacation time of senior high schools in Jiangsu Province is planned to be July 1, and the school start time in September is planned to be 1. In the compulsory education stage, the summer vacation time is from July 7 to August 3 1, and that in ordinary high schools is from July 14 to August 3 1.