As you might have experienced yourselves, even the best plan cannot account for the unexpected, and you will be delayed by things that are out of your control. You might get ill, discouraged, you might be overworked for a while, etc etc. So when creating your long term plans, try to put a few extra days off once in a while. If you don’t use them, great! call it a productivity boost. If you use them, your mind will get an extra opportunity to reset itself. After the break, simply resume your work as if the break has never happened. Trying to ”catch up” with the original plan might backfire because you end up burning the midnight oil just because you had the flu so it’s like punishing yourself for being ill. Just get over the fact that your certificate will wait a few days more for the owner.