The amount earned from subscriptions appearing in your Space earnings dashboard is prorated per day: it shows what you’ve earned per subscription so far.
If a subscriber pays $9/month and it’s been 5 days since they subscribed, the amount you’ll see on the dashboard for that subscription is going to be $9 divided by 30 days and multiplied by the number of days it has accrued since the subscription started - in this case, 9/30*5= $1.50.
You will keep getting 1/30 of the amount of a subscription daily, until the subscription expires.