I learned my 2007 AA was close to matching my risk tolerance but having 10-15% less in equities would have improved the quality of my sleep. I also learned that holding on and riding out the downturn held great future rewards which I am now enjoying.
+1
For me, the recession was a great test of my AA. Naturally I was very concerned, but with my 45:55 AA I was somehow able to hold on to the belief that I would not lose everything, that the market would recover, and that I would be OK. I forced myself to not sell low and even buy low a little bit, as much as I could bear anyway. I am SO GLAD that like you, I held on and rode out the downturn (or, alternately bought low), never selling low, because it made all the difference.
As for how long the 2008-2009 downturn lasted, well, from my (VERY untrained, inexperienced, subjective) point of view at that time, it lasted about 15 months or so, maybe?
When did it begin? The Great Recession became pretty obvious even to me by the fall of 2008. Before that I thought it was just a normal downturn, but in retrospect I guess that was part of the recession. By October of 2008 I felt like the forum was freaking out, except for a few steady folks who I tried to emulate.
Several forum members were posting about moving to Mexico since they couldn't afford to retire in the US. Others planned to delay their retirement plans. At least one or more announced that they were going to sell everything immediately and go strictly cash. I was trying to hang on like a pit bull and wait to see what happened. I really didn't know what else to do. Either this "buy and hold" approach was going to work, or it wasn't, but I bet the farm (as the saying goes) that it would work. And it did - - eventually the market began to recover.
When did it end? My portfolio hit its low on 3/9/2009, when it was just 49% of what it is now. If the Dow had dropped to zero and stayed there forever, as some doom-n-gloomers on financial websites predicted, I'd have been up a creek, but it didn't.
By the time I retired on 11/7/2009, the recession was over although at the time, I didn't know that it was over and financial analysts online were saying the worst was yet to come. But instead the market has surged upwards pretty steadily since then, with only a few comparatively minor blips.