The title of Star Wars: The Force Awakens was revealed in early November 2014, over a year before the film’s release and less than a month before the first teaser.
For Star Wars: The Last Jedi, the title reveal came in January of 2017, followed by a teaser in April and the film itself in December.
We may get a title and a teaser in a couple months, or it might not come until 2019.
If nothing else, Mark Hamill was probably onto something with his first cryptic tweet, there’s a solid chance that Episode IX’s title starts with ‘The.’