PAUL SMITH
2365 S Mayfield Ave
Chicago, IL 60652
Cell: (123)-555-1234
[Subject: Normally bold, summarizes the intention of the letter] -Optional-
DearPAUL SMITH,
I apologize for having forgotten to include the time off that had been requested by you. I completely forgot about it while preparing the calendar, and probably I went out of station, so did not even have the time to look over it again. I have re-timed it for Saturday, Monday, and Tuesday off this coming weekend. I hope my mistake has not been a source of much contention. I shall try and make sure that this would not recur again.
Sincerely,
Alok