How do you edit the time intervals for scheduled reports?

I need to change the time intervals for scheduled reports in Sugar. Currently, the only options are hourly, daily, weekly etc but I need it to be "Every Tuesday" and "Every Thursday" at a specific time. 

I cannot see the scheduler interval dropdown in the dropdown editor. 

Does anyone know how to change these intervals? Or, do you know how to add two scheduled sessions to one report without having to write two reports (one for Tuesday and one for Thursday)?

Thanks in advance!