He reschedules but never picks a new date himself

When someone reschedules without saying when they want to meet instead, they're not actually rescheduling. They're just cancelling. He might feel bad about cancelling, or he might not. He might intend to figure out a time later, or he might not. But right now, in this moment, he has not done the work to keep the plan alive.

This is information. It tells you how much effort he's willing to put in. Not how much he likes you necessarily, but how much he prioritizes making plans stick. Some people are just disorganized and do this with everyone. Some people do it only with people they're half interested in. The pattern is the same either way, and your response should be the same. If you want to see me, you schedule it.

The move is simple. You acknowledge his cancellation but you don't become the one who proposes the next date. You name one or two times you're actually free, and you ask him to pick one or suggest his own. Not five options. Not 'whenever works for you.' One or two specific slots, and the ball goes to his court.

This does two jobs. First, it keeps you from spending energy on someone who isn't spending it back. Second, it tests whether he actually wants to reschedule or whether he just wanted to get out of Thursday. If he picks a time, great. You have a new plan. If he goes quiet, or counters with something vague, you have your answer too.

Send your reply with the specific options and wait for his response. Not three days. Not a week. If he doesn't reply within 24 to 48 hours, the message is clear. He wasn't interested enough to even pick a day.

If he does reply but the reschedule falls through again without him offering an alternative, that's the moment to stop. One flake is circumstance. Two in a row is a pattern. You don't need to make a speech about it. You just let it die. His next move would be to set a time, and he's already shown he won't do that.