For your first pledge, you will be charged for the current month on the day that you start supporting.
After the first month, regardless of when the first payment occurred, the following payments will automatically be made roughly between the 1st and the 5th day of each month.
Therefore, even if you start supporting from the end of the month, you will be charged for the next month at the beginning of the next month.
Your "Support Start Date" and "Next payment" date are listed above the "Become a FAN" button on the payment method selection page.
However, if you choose convenience store payment (only available in Japan), the billing method will be as follows.
Before you start making payments, you can choose to pay for 1, 3, 6, or 12 months. You will start supporting as soon as you've completed your payment at the store.
Your support will cease the month after your support period has ended.
The support period will be displayed at the bottom of "Payment amount" on the payment method selection screen as "Support until the end of Month, Year."