Warp 1 is the speed of light. I don't know where you are sourcing that from, but they must have been traveling at least warp 7.8 on the old scale, or warp 6.4 on the new scale. They must have accelerated to a faster speed or had used a timelapse. There are generally days or weeks in between planets for travel time that are cut out.Warp 1 is the speed of light. c = 299,792,458 metres per second or approximately 186,282 miles per second. Wikipedia has an extensive page on this.

One light-year is equal to:

- exactly 9,460,730,472,580.8 km
- about 5,878,625,373,183.608 miles

Therefore It takes roughly 1 year to travel at this speed.

Warp 1 = 1 /31557600 Light years per second

** 3.16880878 × 10 ^{-8 }**