From the Admin Dashboard, click on the Billing header and then the Overview tab. Click the "Create charge" blue button in the top right corner.

Begin by setting up the first item for the first numerical date of the month that billing will be due. For example, if your charges are due on the 1st and 15th of every month, you'll set up the first item and it's recurring charges with a due date of the 1st.

Click "Save item" once completed. Click "Add item" to begin the same process for the second billing due date of the month, for example, the 15th due date.

Click "Save item" once completed. You should have two items listed with two separate due dates twice throughout the same month. Click "Continue" and "Create charges" in the top right corner.

You'll see in the screenshot above, Samuel Young's guardians are charged every 1st and 15th of every month.