In general, the billing date is on the subscription anniversary. If you want to verify or change the billing date, follow the steps below:
1 - Access https://purchase.hotmart.com/
2 - Login with your email and password (the password is different from the Loot platform, you probably received an email from Hotmart with a button to access, but if you cannot find it, click on "Forgot my password" to receive an email and create a new password);
3 - After logging in, you will see a screen with all your Hotmart purchases;
4 - Click on the desired subscription product. Then, select Set Up Payment under the tab on the right side;
5 - A new page will open and you can see your details in the Payment section.