Inquiry regarding the interpretation of the invoice payment term "Due the 10th"

I am writing to inquire about how to interpret a specific payment term on an invoice. The payment term written on the invoice is "Due the 10th, 30 days month end + 1% discount," and I am curious about its exact meaning. If we assume the invoice date is January 1st, is it correct to interpret this as "1% discount if paid by January 10th, with a final due date of February 30th"? Usually, discounts are offered for early payment, and since "the 10th" seems to refer to the current month, I am having trouble understanding it because the discount mention follows it. From what I have researched, I suspect the original text might have intended to use a slash (/) instead of a comma, making it "Due the 10th / 30 days month end + 1% discount." I would appreciate your help in interpreting this correctly.