A parsec being a unit of distance (3.26 light-years), and assuming the dialogue is taken at face value to make some kind of sense, Han’s boast of “less than 12 parsecs” apparently wasn’t his time. Perhaps it’s was a contest to get to arrive at the finish point in the shortest possible distance?!
I couldn’t tell you how long it took him, but the reason that he is known for how short of a distance it took him to get the Kessel Run done in is because there is apparently a bunch of black holes along the way, so smugglers would take a longer, safer distance from them than Han Solo did.
The Kessel Run was one of the most heavily-used routes in the Galactic Empire. Han Solo claimed that his Millennium Falcon “made the Kessel Run in less than twelve parsecs”. A parsec was a unit of distance, not time. Solo was not referring directly to his ship’s speed when he made this claim. Instead, he was referring to the shorter route he was able to travel by skirting the nearby Maw black hole cluster, thus making the run in under the standard distance. By moving closer to the black holes, Solo managed to cut the distance down to about 11.5 parsecs.
Of course, all of this “background material” is no doubt mere apologetic backfill, compiled after the fact, to cover gaps in intelligibility of a script written for consumption by 12-year-olds, peppered with science terminology that holds up poorly to scrutiny. Should George Lucas have known better? Hard to say.
My personal opinion is that George Lucas’ “genius” only extends as far as editing down and saying no to things that weren’t good enough for the big screen back in the late 70’s and early 80’s. George Lucas teamed with Industrial Light and Magic to create the ground-breaking special effects of the original trilogy (ex: the new camera techniques employed to shoot the asteroid chase seen in Ep. V). Even so, there’s only so much one can do with miniature models, stop-animation techniques, and muppets.
When the original trilogy was re-released in the late 90’s, George Lucas went back and added all of the stuff he wished he could’ve done the first time around… and seriously pissed off nearly every Star Wars fan alive. All the new special effects do nothing for the story and often are distracting.
My point is that, when faced with insurmountable special effects limitations, George Lucas was able to make a universe filled with unreal creatures and activities come alive by actually being creative in the film making process; sticking with what worked and dropping whatever didn’t.
He originally said no to the scene where Jabba the Hut visits Han Solo in the hangar of Ep. IV. Why? Because they couldn’t do it right. The interaction between a live actor and a giant muppet was untenable the way they wanted to shoot it. Then in the late 90’s when CGI had progressed to the point where they seemingly could construct the scene well enough, he added it back for no purpose other than his own hubris. The movie was betterwithout that scene. He had edited it out originally due to technical limitations, but really it should’ve been dropped because it simply didn’t add anything to the story.
The prequel trilogy makes my point for me. It’s a hugely overblown CGI showpiece where Lucas threw in every little “cool” thing he could imagine… leaving us with a dragging story line, almost no wit, and character acting that could’ve been replaced with muppets to elicit a stronger emotional presentation.