School day is a common phrase used to describe the time spent in school by students and teachers. However, there are several other phrases that can be used interchangeably with school day. These include academic day, instructional day, learning day, educational day, study day, and class day. Each of these phrases emphasizes a specific aspect of the school day, such as learning, instruction, or academia. Additionally, phrases like school hours, class hours, and classroom time can also be used to refer to the time spent in school. Overall, these synonyms can help to diversify one's vocabulary and provide a greater variety of ways to describe the school day.