So many ways to enjoy your time off with family/friends without killing your diet. Personally I am not into total cheat days, they screw with my body way too much. But everyone has different goals and for me cheat here and there is OKAY--but entire day throws me off. Way too many carbs and I literally go into carb coma.
Enjoy your day with family. Eat prior to all cookouts and just select healthy options. Lean burgers without buns or go with a low carb wrap option. Have a nice salad and put some chicken on it.
Not saying stray away from the awesome treats, just don't over do it.