You will not hear any horns blowing. Most everything is on Hawaiian Time, which typically means slow and a little late. You will notice that our weather is conducive for a lot of outdoor activities which is why you will see thousands of folks up at the crack of dawn out walking, jogging, or bicycling. The sunrise is as beautiful as the sunset. It's casual all the way.
Women dress casually for just about anything except for dinner at the most exclusive restaurants.
Even then, men can get away with a short sleeved Hawaiian shirt and pants. Shoes are optional almost everywhere except, again, at exclusive restaurants. Most locals opt for zorries, rubber slippers, or sandals. Don't be surprised to see bikini-clad women out shopping on their way to and from the beach. Hawaii is known as the melting pot of America where diverse ethnic cultures coexist.