I'm about to finish my master's degree so I've been applying to jobs, many of them state or federal that take a bit more time to hear back from. Two of them contacted me to set up interviews a ways out, which are now coming up. However, due to some personal and mental health reasons, I made some commitments this summer now and will not be available for work until September. None of these jobs have start dates listed but I feel like since they're interviewing now they probably want someone to start before then.
I don't want to waste their time or my time if they definitely can't wait that long, but is it appropriate to email the hiring manage and just let them know my availability? Or should I still wait for the interview to be conducted and tell them then?