Nobody can give you a date, and anyone who does is selling something. But the phases have shapes, and they are predictable enough to plan around. What happens in each, what speeds it up, what stalls it, and the monthly check that tells you where you are.
What Wikidata is to Google, the notability bar for a person, the handful of properties worth adding, the exact way to attach references, and why a thin entry does more harm than none.
A panel that was there last month is gone. The one minute test that tells you whether the entity still exists, the five causes behind most disappearances, what to fix for each, and why the one thing not to do is build a second version of yourself.
What Google's knowledge graph actually is, how a person gets into it, why it sometimes holds two versions of you, and what the kgmid code in a search address tells you about your own entry.
Some services selling knowledge panels are honest consultancies and some are a Fiverr listing with a Wikidata account. The four questions that separate them, what each type actually does, what a fair price looks like, and the one word in a sales pitch that should end the conversation.
The sequence that actually produces a knowledge panel for a person, in order, with the common mistakes that stop it from working.
Two of the most common questions about knowledge panels, answered plainly. Google does not sell them and does not charge for them. What costs money is the work, and the cheapest version of that work is the one that gets the panel removed.