Time Differences

Doing business with someone in Germany totally stinks. There is a 7 hour time difference, so in order to have conference calls, the American has to be up really early. When I was working with a university in Austria last year, I would have to schedule my calls for around 4 am in order to get in touch with the people I needed to. Now I am calling from an office on campus that doesn't open until 8 am, so we have to have many short conference calls because my contact in Germany is about to go home when we call. So now I have to get up early on my only free day this weekend to make a stupid conference call. I know they're paying me so I should do what works for them, but couldn't they be inconvenienced just once or twice and take a call around 6 pm their time? I'd better get a free trip to Germany out of this consulting job or I'm going to be thoroughly annoyed.