Contact data subscriptions are on a monthly plan and are automatically scheduled to auto-renew.
To find out when your subscription is scheduled next, click on Account in the upper right-hand corner of your screen, then select Account Settings.
From the left navigation, select Subscriptions & Billing.
Under the Payment and Billing section, click View Invoices.
From here, you should see any previous/active subscriptions associated with your account. In the example below, I see my active subscriptions for Contacts and Crunchbase Pro (notated with arrows), which were purchased on June 17, 2021. Additionally, I see the next monthly payment for Contacts will occur July 17, 2021, following that will be a monthly payment on August 17, 2021. Also highlighted is my Crunchbase Pro auto-renew date which is June 17, 2022 (Crunchbase Pro auto-renews every year).