It took me 6 weeks.
I started a project to find proper evidence for all I believed. Within 6 weeks I became convinced there is no reason to believe in God, a divine origin of the Bible, and found the JW religion dishonest and despicable.
That last week I appeared on good ol JW on Tuesday, told my wife on Saturday, and never went back to another meeting (thanks to my wife insisting I wouldn't join her to meetings as that would be hypocritical.
Or maybe it took me 30 years...I was born in, always believed....but my heart was never fully in it....as if my subconscious knew something was wrong.
Anyhow, speed isn't too important. Mental health and happiness are.
Some need more time. Some stay PIMO many years too long because they fear their family. In the end it's a big gamble for all of us. Problem is we have just this one life and shouldn't spend too much time trying to please others or spare their cult-controlled feelings on our own expense......