Twice (starting new enterprises) if it weren’t for a couple lucky breaks I’d have needed at minimum 18 months. As it was, I burned down about 6 months worth the first time before starting to break even. The second time it both took off and crashed quickly and I didn’t burn much cash during the enterprise itself but did spend 3 months after unemployed and looking for a 9-5 job.

A third time (joining an early stage startup as a late founder) 6 months would have been a decent contingency if it went under fast, 12 if it withered away slowly. (Also caught a lucky break on that one and had a soft landing.)

Once (walking away from a bad job and looking for one that was a stretch), 6 months would have been plenty because if the gamble didn’t work out I knew I could reset my sights lower after a few months of looking and be employed somewhere within 6 weeks.

So the answer is very much “it depends on the circumstances”.