If I made this ahead of time...?

Your lemon lime carbonated beverage must be added just before serving or your punch will be flat. This is such a simple recipe, that I can't figure out why you want to make it ahead of time. The only items that require measuring is the 8 scoops of ice cream which you can do a week ahead of time and the 1 cup sugar, measure out the sugar and put in an airtight plastic container. It should take you less than five minutes to combine all the ingredients for the punch.