An active subscription is renewed every month on the day, that you have originally purchased it.
Live Score will create a new bound order on the beginning of the provided renewal date in the timezone of Berlin / CET (CEST).
You can always see the next renewal date in the list of subscriptions in your account.
If you want to read more about subscriptions, please see this page: https://www.live-score-app.com/userguide/subscription