What stretches or shrinks the timeline.
"Three to six months" is the median, not a promise. These six factors decide which end of it you land on.
Your competition
Displacing a forum thread takes weeks. Displacing a law firm that's spent five years building content takes a year. Same work, different opponents.
Your site's age and history
An established site with clean history moves fastest. A brand-new domain starts from zero trust. A site with past spam or penalties has to dig out of a hole first.
Your starting condition
If the site is fast, crawlable, and half-decent already, month one's fixes unlock rankings you nearly had. If it's held together with duct tape, foundation work eats the early months.
How much gets done per month
Budget buys hours, and hours are the throttle. Four improved pages a month reaches the destination sooner than one. This is the honest way to "speed up" SEO. (It's also why pricing and timeline are the same conversation.)
Which searches you target first
Chasing only the biggest term means months of nothing, then everything. Winning long-tail questions first produces calls during the wait. Good strategy sequences both.
How often Google visits
Small sites get recrawled on Google's schedule, not yours. Fresh content and a submitted sitemap coax it back sooner, but some waiting is physics, not failure.