On those rare occasions that I just can't stay within my daily calories, I will post the excess calories as part of my meals for the next day. I eat carefully that next day packing the most nutrition into few calories. This keeps me on target for my goals without depleting my body of the fuel it needs.
This isn't something you want to do every day! It's for that occasional over indulgence. I wouldn't post more than 200-300 calories for the next day to ensure I get enough calories to maintain my energy level.