Originally Posted by mvnsnd

It unfortunate that people hold on to these beliefs in this age. However, your instinct is correct that you have to sit with these people and stress to them the significance of what is happening. It is out of your control, and this type of person may also then claim that since these people who come in late work for you and you can't remedy the issue, you are part of the problem. Have a discussion, write down a summary of the discussion with each immediately afterwards and file for yourself. Be compassionate and transparent as to where its coming from. You don't need to explain more. Be aware that a reaction to this will be these employees working to a clock though; in at X, out by Y, no extra time. That's the usual push-back along with a decrease in morale.