When I was flying Part 135 Cargo in turboprops, I got a class date for a pretty good Part 135 Jet Charter operator about a month away.
I had my resignation form filled out and signed, but wasn't going to give a day more than 14 days notice because this was still the kind of place that might 'fire' you on the spot instead of accepting your resignation...
Until about 17 days out, I got a phone call before the last leg of my run telling me that I was going to be staying at the next/last stop for the weekend instead of flying home in order to let another fresh pilot use my plane to recover a broken one on another run. While on the phone with dispatch, and being plenty cordial, I was prepping a fax of my resignation form to send in the second that I hung up the phone. I knew the fax machine was sitting next to the dispatcher that I was on the phone with, but my favorite part was that instead of calling ME back, the ACP called the FBO to make sure that I was still there and to see if it looked like I was planning on flying the next leg still. That was probably because a lot of people were quitting on the spot and leaving their charts and badge in the right seat at some random outstation.
Anyway. You have to be in the right mood to quit a job, and I was. They ended up being fine for the last two weeks, and my ACP called to congratulate me and thank me for giving at least 2 weeks notice because so many others weren't.