- As per the Articles of the Federation section and galactic star chart in Franz Joseph's 'Star Fleet Technical Manual'.
In 2266, the USS Yorktown (NCC-1704) was enroute to Starbase 6, now under Admiral Benthoven, from Earth Colony 7 bearing the secret weapon, Excalibur. During the voyage the Yorktown was attacked by Andorian rebels in an attempt to capture the weapon. Fortunately, the Excalibur was placed inside a shuttlecraft and escaped. (TOS short story: "The Enchanted Pool", Star Trek: The New Voyages).
A few weeks later, a team of astrophysicists from Starbase 6 board the Enterprise for an investigation and observation of a nearby star about to go supernova. (TOS short story: "Marginal Existence", Star Trek: The New Voyages 2).
- The year of these happenings is based on the stories' placement in the Trowbridge timeline
In 2268, Starbase 6 was mentioned as the closest base to the Enterprise during her investigation of a planet where the landing party ended up being held captive by a robot probe. (TOS short story "The Patient Parasites", from the TOS anthology Star Trek: The New Voyages 2).
- The year of this happening is based on the story's placement in the Trowbridge timeline
Starbase 6 was still operational in the 24th century. In 2365, the USS Enterprise (NCC-1701-D) transported Kareen Brianon to Starbase 6 from Gravesworld following the death of her mentor, Dr. Ira Graves. (TNG episode: "The Schizoid Man").