Yes possible check the Week days value and according to that per week activate that code on that day suppose every week Sat Evening or any day use. You have to use same script but in if conditions in first If part use every 30 minutes reload and then in second part use per week condition. By this you get the full load per week.
Definitely, it is possible to have a incremental load and full load in the same document script. You just need to handle them with proper condition. For example, if weekday is sunday and time is in between 9am to 10am than run full load script else run incremental load script.
Please note, since this is running every 30min, you may face issue if the full load is not finishing within 30min.