My approach is the exact opposite, and I get very low flakeg and even the flakes usually end up with a solid later arrangement which is then kept.

I get a commitment to a pre arranged date and I also lay out the "rules of engagement" very clearly:

'If something comes up I'll let you know with plenty of notice, I expect the same courtesy from you of course. Also I will assume its still on unless one of us tells the other its not, even if were not calling/texting each other every five minutes'.

Basically I'm laying it out that I'm a busy but organised and reliable person and I expect them to be the same, no fucking around.

does sex then occur at precisely 23:00 and finish at 23:01?

Yep - 23:00 on friday and 23:01 sunday

I was gonna stick up for the OP as he was shot down after taking the time to contribute to the forum, but since it was plagiarised, I suppose my argument is out the window