In terms of health and physique goals, one day of optimal/non-optimal eating and training will not make or break your results in a year to come. However, to quote Aristotle, “We are what we repeatedly do. Excellence, then, is not an act, but a habit.”
Focus on putting your best into each and every day, and trust that your consistent work effort will compound to future success.
Remember, becoming an overnight success takes ten years.
The time is going to go by anyway, therefore make your daily actions count so they can contribute to something GREAT.