When my fiance and myself were setting a date to get married, it didn't take us long. We knew we didn't want to drag it out too long, so we set the date for three months down the road.
So my father in law (to be) pulled me aside one day and said "Brad, you gotta ask stand your ground. Don't ask for permission to marry on that date. Don't make it optional. Just say how it's going to be."
I was impressed.
So next time I got hassled about the date, I promptly responded "hey, is this your wedding or is it mine? If it's yours, you get to decide. Now that it is mine, you know what has been decided!"
And that is how I ended wedding arguments down the road.
We got'er done and lived happily ever after :)