Assuming no earnings on savings/investments, no retirement income, and my current lifestyle, approx 166 months.
Assuming a smart investment program and fairly drastic but "realistic" lifestyle changes, indefinately. No limit whatsoever.
If I was not married, it would be an unqualified "indefinately".
I don't spend much and I've been saving a minimum of 10% of my income for the last 12 years. Every dime my wife has made since we've gotten married has gone into savings. I refuse to be in debt and have never carried a loan except for a few years where I made more in investments than the loan interest rate, so the loan paid for itself.
Yea "the man" owns me for 9 more years, but lifetime fiscal independence at age 42 is a reasonable payback for what will work out to just under 25 years of service. All I have to do is stay off drugs and don't get a DUI. That's apparently too hard for some people, but it's not a very tough decision for me personally.
But my parents taught me to take the "long view" on life from a very early age, so I was planning my retirement before age 15. That sure made certain career decisions easy.