When your guests arrive at your ceremony, here's how they're feeling:

They're hungry. They know you're a classy couple who's going to serve them delicious food, so they saved their appetites for it.
They're thirsty. In a manner of speaking. Many if not most of them will be looking forward to the free booze that comes with that delicious food.
They're eager to socialize. Weddings are premier social events! Everyone is looking forward to catching up with the people they know, or getting to know the people they don't. 
They're looking for something great to talk about. There are good vibes in the air, and everyone wants to praise you - for how great you look in your finery, your exquisite taste, your top-notch party planning skills, and for what makes your wedding day memorable to them.

Your people have needs, friend! What's the best, most direct way to meet those needs - and maybe give your pal Tim an extra hour to arrive and rock your ceremony? It's simple: swap cocktail hour and the ceremony. Have cocktail hour first.

Raising the Bar

When you have your cocktail hour first, followed by the ceremony and then dinner, these are the benefits:

Everyone rejoices at the sight of your mouthwatering hors d'oeuvres when they arrive. They thought they were going to have to wait!
Everyone rejoices at the sight of your open bar. And when your ceremony begins, those drinks will translate into more smiles and laughter, especially during the funny bits!
Everyone gets a dose of dopamine (a dosamine!) and a smidgen of serotonin (a smidgotonin!) It's been shown in actual human studies that social interaction stimulates the release of our "happy hormones" - aside from being its own reward, this also leads to more smiles and laughter throughout the ceremony.
Everyone immediately has that great thing to talk about. You'll hear it right away, as your guests eagerly and gratefully eat, drink and revel in your hospitality - how great it is that you started with the party, and how this is the only wedding like it that they've ever been to. Your wedding is immediately unforgettable.

The Foine Print

This plan, for all its benefits, does have some specific requirements.

It requires you to see each other before the ceremony. Many couples will buck tradition and see each other before the ceremony anyway (for photos, ease, each other's company, or all three) but if you simply must remain out of each other's sight beforehand, that's the tree that eats this kite.

It requires you to actually have a cocktail hour. Obviously, if you're not serving alcohol, it usually means you're not having a cocktail hour. 

It requires a few of your other vendors to agree to the change in your itinerary. You'd need to first clear this change with your venue, as well as your caterers, bartenders and security, if those services aren't already provided by the venue. In addition, you'll need to check with your photographer to determine how it affects their carefully planned timeline as well.

Worthy of Your Whiles

Depending on where you are in your wedding planning, making this tweak to your schedule might be a breeze, or it might require a fair amount of legwork to arrange. No matter which case, know that the effort will yield more than just a great ceremony. With all their needs met - appetite sated, drinks imbibed, loved ones loved - your otherwise great ceremony just became an epic one.