Impression from movie is that it took at least two days for Rebels to arrive at Ednor from Sullust (Sullust as starting point is supported by both novelization and movie).
Light positioning has changed by around 30 degrees, which gives us 2 hours as minimum.
However, fleet has jumped at hyperspace at 1:24:10, and arrived at 1:31.
With that, we can see that sun changed position by at least 9 to 12 degrees. That corresponds to timeframe of 36 to 48 minutes. However, that would have Ewoks construct awful lot of equipment in short time, so actual time is t+timeframe.
Ewoks made awful lot of preparations: constructed catapults, dug holes big enough for AT-ST to fall into one, made traps, and dammed a stream.
We see that Rebel fleet was inside galaxy when it started, and novel mentioned world Sullust. However, only indicator for distance we have is fact that Ewoks succeded to dig two holes in ground, big enough to accomodate AT-ST, presumably at least up to guns so they can't fire anymore.
According to this page, AT-ST is around 5 meters long with guns and 7.5 meters tall, with 5.5 meters being minimum depth of hole. That gives us diameter of hole as 5.5 to 7 meters, and its depth as 5.5 to 9 meters. These values give us volume of each hole as being 131 to 347 cubic meters.
Extent of hole is 17.28 to 22 meters, allowing us (assuming each ewok needs 1 meter to do job of unloading baskets with dirt coming from bottom without hinderance) 17 to 22 ewok teams, each having one digger. That means that each ewok has to remove 7.7 to 15.8 cubic meters of dirt. If we take each ewok can remove 2000 cubic centimeters of dirt per shovel, with one shovel every ten seconds (else they would tire out fairly quickly, and too many crew changes in too short time drops effeciency drastically), we have 3850 to 7900 shovels. That is 10.7 to 21.9 hours. And that is even not considering moving all that dirt to somwhere else.
This means that preparations for battle alone took 1 or 2 days at minimum, possibly more (up to 5 days). With Rebel fleet entering hyperspace few hours beforehand, we have timeframe from 28 to 53 hours low end, with 125 hours high end (given volume of job Ewoks done, high end is probably closer to truth).
Distance from Endor to Sullust is in "hundreds" of light years, giving us distance of 200 to 999 light years.
CONCLUSION: Hyperdrive speed is 312 758 c high end, and 14 000 c low end.
Hyperdrive cannot engage from close to planets.
