Fifteen to twenty years ago, the mediation that lasted until midnight, and beyond, was not uncommon. My mediator colleagues and I would get together and astonish each other with tales of wee-hours of the morning negotiation.
I never thought that the “all-nighter” was a good idea. Without good reason (jury trial starting next week?), why expose your client and yourself to the vulnerabilities produced by pure weariness? We are not meant to think clearly at 3:00 am. Fortunately, this practice seems to have faded. I think in the last ten years I have only had three mediations go past midnight, and one of them lasted until 4:00 am. That they were all in the span of thirty days in February of 2012 is something I will never understand!