One week to reach final gravity?

Eight days ago I brewed a light orange ale. The starting gravity was right on. I went to move it to a secondary (there was ginger root in the recipe and I didn't want any more ginger in there passed the primary, so I moved it to a secondary to get it off the cake). I took a reading while moving it, even did it three times, and I got consistent readings that suggest I've reached what I want for a final gravity. How did that happen? Should I bother with keeping it in the secondary? Should I just carb it and drink it?

When you say you did it three times, you mean over the course of three days, right? If so, then yes it is entirely possible for fermentation to be complete in 8 days or less. It could probably use a week or two to condition and clean up a bit, but you certainly could go ahead and bottle/keg it now as long as the SG has been stable for a few days...

Secondary fermentation is not primarily to drop gravity, though it does happen. Secondary or extended primary time is to give the yeast time to clear up some unwanted compounds that they produce during fermentation. It also gives a time to flavors to mellow or meld and also time for yeast, etc. to settle out and clear the beer. I make large heavy beers (Wee Heavy, RIS, etc.) and my gravity is pretty close on most of them within a few days. Hitting your gravity in that time is no surprise. However, being on gravity only means the yeast have made the alcohol you wanted. It doesn't mean their job is completely over. They've made your beer, now let them finish cleaning it up.

If you didn't think it was at gravity, why did you think it was time to rack to secondary? I secondary many things when making fermenter additions or doing extremely long bulk aging, and until about a year ago still secondaried everything. Nothing went into secondary though until the gravity was about where I wanted it. I know many will tell you 1-2-3 weeks (primary for one, secondary for two, bottled for three), and used to follow this myself. However, it is not that hard and fast. You secondary after primary fermentation is over. You bottle when secondary is over (if using a secondary).

Continue with your plan of letting it secondary for a while. You could probably carb and drink it right now, if you like it, but most things benefit from some amount of aging. I assume with the style you only planned to secondary for a couple weeks, so don't rush it.

Thanks for the advice. This was the first brew that I developed on my own. I knew where I wanted the alcohol to be (4.5-5%), so based on the original gravity, I knew where I need the final to be. Since all of the other brews I've done have been from other's established recipes though, I guess I just fell into the notion that you move to a secondary after a week. I moved it to get it off of the yeast cake in case any of the ginger would impart a weird taste if it sat too long and also I was eager to try yeast washing for the first time. I assumed that it was in the secondary that the gravity continued to drop, but I was wrong it appears.

I think it tastes quite good now (sweet orange peel, ginger root and acacia blossom honey) and would like to put in to bottles to carb up as soon as possible, but I'll continue to let it sit for awhile to clear out as long as the gravity won't continue to drop too much.