Is it appropriate to say
'Sorry for making this hard for you'?
Some context: We tried to set up a time to meet but we have conflicting schedules so we decided to meet later at night.
I presume that you do not wish to suggest that it is the other guy's fault. If you say it is hard for them, then potentially someone else would not find it so hard - so it is their fault!
So you must therefore imply that only you are to blame. One way of saying that would be to say "I am sorry to be so difficult..."