如何在一周中的特定日期重复本地通知（iOS Swift 3）

I am creating my first app that lets the user set alerts for themselves and then the app would send the user a local notification on the set time. The thing that I'm having trouble with now is being able to fire the local notification on specific days of the week (for example every Mondays and Tuesdays only). All the tutorials/questions that I have come across so far (like I am creating my first app that lets the user s