This question should be asked more often. Let us share some of our observations.
The time-line we frequently see is not the one we'd recommend because we find it inconsiderate of your guests. (And you’ll find I’ll use the word “inconsiderate” quite a few times in this article. To me, it’s the ultimate sin of a bridal couple when they are hosting their post-wedding celebration.) The couple tends to serve the meal to the guests, have the toasts, the first dance, the "this", the "that" and FINALLY, about 30 minutes before they leave for the night, they will remember they have a pretty ornate cake they need to cut and allow it to be served to their guests.
But what has happened is many of their guests have already left. The couple ends up with a lot of cake left over, and some guests who left disappointed because they didn't have the opportunity to share in the couple's wedding cake celebration. Guests are gossiping about the rude Bridezilla who never got around to serving them cake, and the bride is crying because “….the bakery sold me too much cake!”
When I said “be considerate of your guests”, that means you should recognize that not all of your guests are young, vigorous, and energetic. The older guests don’t stay out late and party-hardy anymore. They prefer to go home earlier in the evening. Guests who have small children, who are getting tired, bored and irritable, will want to take them home to put them to bed (and if the kids are getting grouchy, you’ll WANT them to go home early!). Other guests may have a babysitter who they need to get home before it gets too late.
Let us also point out that your wedding cake is the only thing at your reception that is designated "wedding". To many guests, the cake IS the reception. Your DJ's music isn't "wedding" music (you had that at the church), your food isn't "wedding chicken" or "wedding salad". But your cake is "wedding cake" and the only place to get it is at a wedding.
To time it so that many of your guests have to leave before they share in the cake cutting ceremony (and it IS a ceremony...as much a part of your celebration as the Best Man's Toast, the First Dance, etc.), is very inconsiderate (dare we say “rude”?) to your guests. Not to mention that you paid for 200 servings but ended up only using 75 (yes, we've seen it happen!)
I had one groom who wanted to order only 75 servings of cake for his 150 guests because “…..you always have a lot of cake leftover ‘coz no one eats it.”
I said, “No. There’s a lot of cake left over because it was cut too late in the evening and there was no one LEFT to eat it.”
What we recommend to our brides (and trust me, most (if not all) of the wedding plannesr, magazines and wedding websites will totally disagree with me, but I'm not concerned with their opinion ... I'm concerned about your guests):
Shortly after you arrive and before the meal is served, do the official cake cutting photo with your photographer. Since the cake cutting ceremony is traditionally the first "meal" shared by man and wife, it is logical that they share this special bite of cake before they open their buffet.
The cake-cutting event is now taken care of and out of the way. The couple can sit back and enjoy their family and friends and not have to worry about yet one more thing that they have to do. Your caterer is able to cut the wedding cake after the meal, when he/she sees that your guests are ready for dessert.
This can save you money in photographer time, also. If your photographer charges you for flat time (i.e. 4 hours), then you want to eliminate any reason to keep him for "overtime".
So please, as you plan the timeline of your reception, think about your guests and how much they are looking forward to a taste of your luscious wedding cake. Time it so everyone can enjoy it and serve it at the end of the MEAL, when dessert is supposed to be eaten.