2 interviews on the same dates

[esoryma]

A couple of weeks ago, I received an invitation to interview at my top-choice school. Of course I accepted the invitation, indicated my weekend-of-choice (they had two options), and the office made travel arrangements for me (flights, hotels, etc.). However, I just received an invitation to interview at another school (which is still *one* of my top choices). They only have one interview date option, and it is the same weekend as School #1.

As School #1 is my very top choice, and School #2 sent their invitation way after my travel arrangements were already made, I am going to decline the invitation from the latter and ask if a phone/Skype/rescheduled interview would be possible. However, I am not sure if it is kosher to tell them why I can't make the formal recruitment weekend...do I tell them it's because I'm interviewing at another school? Or should I just be vague and say that I have "a previous commitment that cannot be rescheduled" or something like that?

(It's especially frustrating because the schools are in the same city! They're literally a 15 minute drive from each other...I wish their days overlapped a little differently so I could attend both in one trip...)

Sorry, I posted this topic in the wrong spot. Clearly I am awesome at the internet.

Edited January 30, 2011 by esoryma