A more thorough explanation:

Definition: Days of grace refer to a period of time during which a person or entity is given some leniency or exemption from certain rules or obligations.

There are two main contexts in which the term "days of grace" is used:

1. Grace period: This refers to a period of time after a due date during which a payment can still be made without penalty. For example, if your credit card bill is due on the 1st of the month, you may have a "grace period" of 10 days during which you can still make a payment without incurring late fees.
2. International law: In the context of international law, "days of grace" refer to a timed exemption from prize law that is granted to enemy merchant ships when they are caught unawares by the outbreak of war. This means that if a war breaks out and an enemy ship is caught in a port, it may be given a certain amount of time to leave the port without being seized as a prize of war.

For example, if you have a credit card bill due on the 1st of the month but you don't have the money to pay it until the 5th, you may be given a "grace period" of a few days during which you can still make the payment without penalty. This is a common practice in the credit card industry.

In the context of international law, "days of grace" were often granted during times of war to allow enemy merchant ships to leave a port without being seized as a prize of war. This was seen as a way to show some leniency and avoid unnecessary conflict.