The best approach to this type of situation is to know your audience. In this case you would be proposing this idea to middle-Aged, middle class educated, working adults who probably also have children of their own. You would need to ask yourself what the concerns, the needs and desires of these adults are with regards to scheduling.
Educated adults respect established facts that have been proven by accurate and unbiased scientific research and most researchers agree with the fact that there is a time lag between traditional school times and the sleep cycles of children, pre-teens and teens. Underage students need to sleep at least between eight and a half and nine and a half hours every night and they also naturally wake up later than adults. When they start their school day later they are more well-rested and alert and more serene and focused in class. Such measure would not only be based on sound scientific research but also on what is best for students with regards to their physiology. Educated adults who are also parents want the best for their children so they would also be receptive to the argument of children’s welfare.