A more thorough explanation:

Term: Solvit post diem
Definition: Solvit post diem is a legal term that means "he paid after the day". It was used in the past in debt actions on a bond. If a defendant had not paid a debt by the due date, but paid it before the lawsuit was filed, they could use this plea as a defense. Example: John borrowed $100 from Jane and agreed to pay it back on January 1st. However, John forgot about the due date and did not pay Jane until January 15th. If Jane sued John for the debt, John could use the solvit post diem plea as a defense, since he paid the debt after the due date but before the lawsuit was filed. Explanation: The example illustrates how the solvit post diem plea could be used in a debt action on a bond. John did not pay the debt on time, but he paid it before Jane filed a lawsuit against him. Therefore, he could use the solvit post diem plea to defend himself in court.