Reception Only Timeline

I an having a destination wedding in September, with a reception for everyone to celebrate with us in October. Since we don't have the ceremony before the reception or have to worry about getting pictures taken in between, we don't plan on having a cocktail hour. I can't be ready until 5 pm the earliest because of my hair stylist's schedule. I can be completely ready before that to head on over to the reception hall by 5:30. But what time should we put on the invitations for the reception "start time" and how long should we give people to get there before dinner starts? Do guests usually arrive right at the start time, or do they usually come just in time to make the dinner? Should we (newlyweds and wedding party) arrive just before dinner, or half an hour before, or what? I have the caterer and DJ booked, but haven't given them a timeline yet, and I need to get on that soon so they know what time to come in and set up.