What's the jealousy speaking to?
That you don't get to see him til Sept and the other person is seeing them NOW?
Would it be better if you did not know his calendar items?
I haven't really been commenting because it did start to feel like your diary where you work stuff out for yourself.
I know I could comment if something struck me but I thought your questions were in the "asking things out loud to myself" bucket.
Sorry if it seemed slow to respond.