We value your work with us as an employee, and we hope we can continue procuring your services on mutually-beneficial terms. As we discussed on [DATE, ex. June 10, 1998], the company greatly values your time. For this reason, late arrivals at the office blemish the quality of the service you provide.
With city congestion and the difficulties of transportation, occasional lateness is indeed reasonable to expect. Unfortunately, however, you have been [X] to [Y] minutes late, on each of [Z] occasions during the past month. Regrettably, this is unacceptable. If you are late more than once in the next month, I will be forced to review your employment with our firm.
[FIRST NAME, ex. John], if there exists an extraordinary or exceptional circumstance which prevents you from arriving at the office on time, please contact me and we will discuss the situation accordingly. Otherwise, I am confident that you will return to your past history of exceptional performance and that the matter will be immediately resolved.
Please contact me at your earliest convenience.