Agreed. My schedule is exactly the same as yours (ceremony at 5:30, cocktail hour at 6, reception at 7) and I didn't indicate AM or PM on my invitation. I didn't feel it was necessary, and I had a professional stationer helping me with the wording of my invitations, so I trust her judgment.
Clear liquids, including water, clear tea, black coffee, carbonated beverages and fruit juice without pulp, up to two hours before surgery. Very light meals, like toast and tea with milk, up to six hours before surgery. Heavy meals, including fried or fatty foods and meat, up to eight hours before surgery.
Prepare the patient for post-surgery diet: the pre-op diet is very similar to the post-surgery diet (reduced calorie, high-protein, low-fat, low-carbohydrate) and will prepare patients for the new way they will be eating after weight loss surgery.