Continuity mistake: At 38:20, T'Pol (as acting captain) says that they have resumed their course to Azati Prime; however, from 39-42 minutes, Captain Archer and Trip discuss the "current" status - that they are still orbiting the planet and then the Captain orders Trip to tell Travis to set a course for Azati Prime at maximum warp. (00:38:20)
Continuity mistake: The captain's log date of Jan. 8, 2154, doesn't align with the timeline of previous episodes. Harbinger, two episodes earlier, was said to take place Dec. 27. The episode in between that and Hatchery, Doctor's Orders, wasn't given an on screen date, but T'Pol compared the anomaly in that episode to the one in Harbinger, which she said was encountered a few weeks earlier. Even if that was just two weeks earlier, that would put Doctor's Orders at Jan. 10, and that episode spanned at least four days, so the earliest Hatchery could take place would be Jan. 15.
Answer: Warp factor has always been inconsistent and hard to pinpoint, or there's too many episodes that contradict the conversion rates. Changes were made in converting warp factor into actual speed between TOS and TNG. It seems ENT reverted back to using TOS method, which is "warp factor cubed" equals how many times the speed of light they traveled. So warp 4.5 means 91.125 times the speed of light (c). Although in "Broken Bow", with the travels from Earth to Neptune and back in about six minutes means warp 4.5 is about 86*c. However, in "The Expanse" episode, warp 5 was 200*c (instead of 125). 1 ly at 91.125*c is about 4 days, but 100 ly would be 400 days.
Bishop73