The closest Federation starbase to the point where Q flung the Enterprise-D in 2365, still more than two years away at maximum warp.
Starbase 185 is a Starfleet base named in the Next Generation episode Q Who. It marks the edge of known Federation territory in the direction of System J-25.
When Q hurls the Enterprise-D some seven thousand light-years across the galaxy, Data works out that the nearest Federation facility is Starbase 185, and that reaching it at maximum warp would take more than two and a half years.
The figure makes plain how far beyond help the ship is when it meets the Borg for the first time. The crew never has to make the trip, because Q returns the Enterprise to its starting point once Picard admits that he needs him.