We are friends with Couple A and Couple B, who are also best friends with each other. Groom B is going to be best man at A's wedding, and maybe vice versa (although I'm not totally sure).
Couple A got engaged 3 or 4 months ago and booked their wedding for September 2013. Couple B got engaged a couple of weeks ago. They were also looking to get married in September or October 2013. They looked around a few venues and found one they really liked, but the only date that was available in their time frame was the week before Couple A's wedding. Couple A are upset about it, presumably because they think Couple B are upstaging them. We are all in the same circle of friends, so quite a few of the guests will be going to both weddings.
I'm sure Couple B could have chosen a different date (ie. not in their Sept/Oct time frame), but it's not what they would prefer. I'm not sure of all the reasons they picked this particular time frame, but I suspect it's a combination of having enough time to save up money, not wanting to pay middle-of-the summer wedding prices, and not wanting to get married in winter. Possibly it could also be to do with where they want to go on honeymoon and picking the right season for that. Either way, I'm not sure if the reasons are particularly important.
Things have turned a bit sour, which is a real shame and has put us and some other friends in the middle of everything. So, who do you think is being unreasonable? I can understand where they are both coming from, but am feeling that Couple A are being a bit unreasonable.