Lightning
Master Member
Between the time Gandalf realized that Bilbo had left Frodo the Ring, & the time everyone met at Rivendell to begin the fellowship, there were SEVENTEEN YEARS where Gandalf was trying to find the origins of Bilbo's ring, & during almost the entire 17 year period, he & others (like Aragon) were actively hunting for Gollum.
By contrast, from the time Frodo leaves the Shire until he returns is about ONE year.
That's how it is in the books, but in the movies the gap between the birthday party and Rivendell is much shorter, perhaps even the same year.