Hi Peter,
If you do not have specific day requirements, then pre-assigning days to routes is just a suggestion. You could always leave them as a generic route name and then decide which route to do on a specific day separately. The naming of the routes in this case will make no difference to the solver.
If you do end up having some orders that need to be done on a specific day you can use the specialties fields like we set up previously for the drivers to account for this. You could have a specialty for a specific day and do a one to one type relationship like we did for the drivers or you could say it has to be done on a Monday, for example, and then all of the routes that correspond to a Monday would get that specialty.