Grandpa Li was sent to the nursing home by his son, who said, "Dad, I send money on the 1st of every month, don't worry."

The first month, the 1st arrived, but the money didn't arrive.
Grandpa Li waited until the 3rd and called his son.
The son said, "Oh, I forgot, I'll send it tomorrow."
The next day, he sent the money.
The second month, the 1st arrived again, but the money didn't arrive.
Grandpa Li didn't call.
On the 5th, the son called and said, "Dad, the money has been sent, I've been too busy these past few days."