Good for his mom for refusing to put up with this nonsense. 

Graduations are not among the things you can reschedule. Well, I guess the Class of 2020 technically did reschedule some of their graduation ceremonies for 2021, but those redo ceremonies were not the same. Graduation ceremony dates are set in stone years before they actually occur, so grandmas and grandpas can buy their plane tickets and plan so they can make it from Florida. 

Weddings, on the other hand, can happen literally any weekend of the year. You might not get the venue you want, and certain weekends might push you over budget, but you can always choose your wedding day if you’re willing to compromise on other things. Most brides have to compromise on something for their wedding, whether it be the flowers or the season they get hitched. If you can’t plan an event that works for you and your family, you might have better luck getting married at the courthouse.