Answer:
June 30
Explanation:
According to the revenue recognition principle, the transaction should be recorded in the books of accounts when the sale is made. It records that revenue which is earned and the possibility of the receipt of cash should be high.
It records that when the product and services are sold to the customer and in return customer received it. Whether the payment received later but the sale is made.
So, on June 30, the revenue should be recognized.