My first million took 20 years. 2nd million took 4 years.
A lot of us FIRE'd after the first, so the second is coming along slowly versus if we still had a paycheck.
The first million took me about 5 years (about 8 years of working, but the first three years of working I had 0/negative NW because of the housing crash, so 5-8 years depending on how you count it).
Quit at 1.2MM, now almost 1.8. It has been about 4 years, and I anticipate it'll take another one, depending on market conditions. So 0 to 1MM will be similar to 1MM to 2MM, for me. I'd be content if #3 took the same amount of time.
Expenses are shooting up though, so I'm skeptical.