I think the first twitch I get is to do something with Hyperspace. Hyperspace is another dimension, contemporaneous with real space, yes? Multi-dimensional? Time isn't a constant?
Mix a little Star Trek with your Star Wars, and I think you might have something plausible.
But, also remember that "Star Wars" is space opera. You don't need to go read a book on physics and come up with something that raises Stephen Hawking's eyebrow. You just need something that your players will buy.
So, the hyperdrive chrono-sequencer burned out right when you were making the transition to light speed. Play out some hairy moments during the bumpy ride in hyperspeed (make it unusual--either really long, where the players are running out of consumables like O2 and food, or make the trip a blink of an eye with lots of burn outs and smoke, when the PCs are expecting a trip that lasts 17 hours).
Then, have the PCs enter the Mandalorian era and have to figure out when they are.
Lena: "Where ARE we?"
Captain Burke: "I dunno. The chrono-sequencer is toast, and I've got half a dozen blinking emergency lights. We're going to have to find a place to set down and make repairs."
C-3X1: "Sir!"
Burke: "Not now, C-3X1. I'm busy."
C-3X1: "But, sir!"
Burke: (Ignoring the droid.) "Whaaa....my star charts are corrects...but..."
Lena: "But, what?"
Burke: "Here, look at this. The planets are right, but look at the orbits."
Lena: "The paths don't match."
C-3X1: "But...SIR!"
Lena: (continuing...ignoring the droid) "It's as if the satellite orbits have retrograded over a million years."
C-3X1: "Yes, SIR! That's correct."
Burke: "If you know something about this then spit it out."
C-3X1: "The Gamester's central control unit reports a postion of not where we are but when we are."
Burke: "You've been holdin' out info like that in an emergency?"
C-3X1: "I've been trying to tell you, sir. We are exactly where we are supposed to be, except that we are 7,285.0168 years before we are supposed to be there."
Lena: "That's impossible."
C-3X1: "Yes, ma'am. Yet, the readings remain."
Burke: "Hmm...and that explains the orbital shift." (Beat) "Threx, start a protocol with the Gamester to see what we need to do to degrade our systems to interact with what we know of this part of the universe, 7,285 years ago."
C-3X1: "7,285.068 years, sir."
Burke: "Right. 7,285.068 years. Lena, get on the langcom and see what kind of problems we're going to have communicating. I'm going to tear out that chrono-sequencer and try to figure out how the hell this happened."
C-3X1: "Sir?"
Burke: "Yes, Threx."
C-3X1: "I have more bad news. At this time, this section of space is contested during the Mandaloring War."
Lena: "You're kidding, right?"
C-3X1: "No ma'am. I am no longer programmed as an entertainment droi...."
GAMESTER'S BRIDGE SPEAKERS: "UNIDENTIFIED VESSEL. THIS IS THE MANDALORIAN WARSHIP CLAW. STAND BY TO BE BOARDED."
Burke: "Ok, guys. New plan..."