Pay weekly if only profitable

I am looking at a subscription to a strategy that only charges weekly when profitable. When it profitability determined? End of subscriber week or calendar week. For example, if I subscribe on Thursday would I get charged on Friday (which would not be wise)? Meaning only one day later, or would it be based upon the day that I subscribed (Thurs - Wed)?

It’s based on the day you subscribe (i.e. subscribe on a Thursday, the billing is done 7 days later).