# Set a Billing Cycle Day for Subscriptions

Create a Subscription form in the Finix Dashboard with the new Billing Date field set to the 1st of the month
You can now choose the day of the month a subscription bills, no matter what day it starts. Set `billing_cycle_day` when creating a Subscription to charge the buyer on that day every cycle, or select a **Billing Date** when creating a subscription in the Finix Dashboard. You can also change the billing cycle day on an existing Subscription at any time.

- **Prorated first invoice**: If the subscription starts on a different day, Finix prorates the first invoice so the buyer only pays for the days until the first billing cycle day.
- **End of month handling**: If a month does not include the day you selected, Finix charges the buyer on the last day of that month instead.
- **Prorated updates**: When you change the billing cycle day on an existing subscription, Finix charges a prorated amount to bridge the gap, then resumes full billing on the new day.


Billing cycle days are supported for `MONTHLY` and longer billing intervals, up to `TRIYEARLY`.

To learn more, see [Billing cycle day](/guides/subscriptions/subscriptions-quickstart#billing-cycle-day) in the Subscriptions Quickstart. For request details, see [Create a Subscription](/api/subscriptions/createsubscription) and [Update a Subscription](/api/subscriptions/updatesubscription) in the API reference.