[cstreit]

I'll agree with Wayne on this. Tell the "new" company that you have a commitment to your current employer that you cannot break without causing problems for them. Do explain to them the seriousness of missing the meeting briefly to them so they understand. They ought to respect that. It will speak well of you as a future employee for them.

Give them a handful of alternative times. If they want you they will accomodate. If they push back, get clarification on why they cannot accomodate (need to meet a hire date, etc..) and make your decision. I would speak to your future boss about this rather than a schedulign secretary.