Doctor gives poor sap good news

Poor sap goes to get his daily check-up from his doctor.
The doctor tells him, "For you today I have some good news!"
Poor sap says, "Okay doc tell me the good news."
The doctor tells him, "You have only one day to live."
The poor sap tells the doctor, " How can that possibly be the good news?"
The doctor states while comforting the poor sap, " The bad news is I meant to tell you yesterday."