You can also save days by brushing teeth while pooping.
But on more serious note.
I never liked this kind of an argument/math, its not like you will magically get a 13th month in a year by not commuting.
That said 3hrs commute is crazy, I did it (3.5hrs of total daily commute) as a teen during a summer job. I leant then that its not worth it. Its draining + expensive. Also it cuts into so much of your time that your quality of life will suffer as you have to choose between recovering your energy levels or social life.
Ever since I have a rule to not consider a job if its too far away.
I'm not sure what traffic/commute patterns are like in the SFBA, but some of my friends/coworkers who've left NYC for SFBA seem to love their new commutes. Well, as much as one can like a commute anyways.