Hi, @Charlesharless,
Welcome to the Roku Community!
We understand that you wanted to update your billing date for your subscription. Please be informed that the only way to change the billing date would be to cancel your subscription and then resume on the date you wish as your billing date.
If you need clarification, you can visit our Account and Billing Support page and choose the "Account, payments & subscriptions" category. You should then have the option to talk/chat/email with one of our live experts.
We hope you find this information helpful.
Regards,
Reynan
Reynan L.
Roku Community Moderator