Investing for the Long Term

This article shows that when you start and when you finish is also important:
http://www.nytimes.com/interactive/2011/01/02/business/20110102-metrics-graphic.html

There is a statement: After 60 or 70 years, returns are relatively stable, but this time frame is longer than the relevant horizon for many retirement plans. Actually, this is the real time horizon for a person who starts saving at age 25 and dies at age 85 (i.e. a period of 60 years). There is no need for the investor to cash out of the market at retirement, as the investor needs only to withdraw a monthly sum to meet living expenses.