The day/week that we have National Fair Day would be July 16 through the 22.
You could make a cake because at fairs they have bake sales and they bid them off and they have the princesses go around the area and show everyone the cake. The auctioneer tells the crowd what kind of cake/pie they are selling to the people.
I think that it should be a National Holiday because you get to do stuff with nature, such as animals and you could plant flowers and stuff like that. Or you could be doing stuff at fair whether or not you are already at the fair, maybe you are already at a fair, so you could just have fun riding rides or you could be with your animals having fun with them. We would be celebrating this day on July 16 through the 22.