What Should I Wear To An All-day Celebrity Golf Tournament?

What is the proper attire for an all-day celebrity golf tournament for both men and women? It starts with breakfast and goes the entire day until the open bar/dinner/awards ceremony is over. There will be auctions and prizes, local celebrities, etc. There isn’t a chance to go home and change and I’m not an avid golfer, so my boyfriend and I are kind of clueless!
Do I wear the same thing all day? I know there are golfing outfits but do I have to wear one of those? Should I wear a skirt and should he wear khakis?