We have an agile team and nearly running 80. sprint.Our sprint starts wednesday and finish Tuesday 10 days after.One of our team member,developer, will attend to a university course every Wednesday during 4 months.Which one is better should we take sprint days Tuesday to Monday,total sprint day will not change still 10,or one member will not attend to sprint plans and team will give commitment for her.
You cannot commit for someone else.
So check with the customer. It will probably have an impact on other planned meetings (sprint review, retrospective, ...) and if it is OK with him, change the day. Explain why you want to change the day. It is always better to have the entire team on board for the planning meeting.