Like some here, I am a fan of and primarily use Spark. It works very well for data 12 months back for time adjustments. There's a more recent inclusion I discovered here on the Forum, Valuation Labs, which is free to use (refreshing in comparison to many appraisal tools that want to gouge the appraiser). I created a custom export from my MLS and gave it a whirl. My initial export did not work so, I sent it to the creator of the program and they got back to me very quickly. You have to be dead accurate and label the export "exactly" like example CVS.....no extra spaces (like I had) or it won't work.
It requires 2 years of data for it to start to calculate. The time adjustments in comparison to Spark I found to be different. Seeing how I've only used it a couple of times.....it might be user error. It's a pretty slick tool although I have to play with it some more so, the jury's still out on that one. Another tool I use to verify time adjustments is "InfoSparks" which is included with my MLS. It too produces different results however, it's more broad and you can't dial in the exact range of GLA, year built, and market area like you can with Spark. But you can go 5 years back in time which is beneficial.
Different tools, different results. It's hard to meet the demand of the new trend of "exactness" that some clients want. Case in point, the sample of the way the GSE's want time adjustments in that graph where there was a different time adjustment each month.
Appraising Real Estate isn't an exact science. As I garnered more experience in doing this... I thought that the appraisal should be concluded with a tight range, not an "exact" number. That way, the lender has some wiggle room instead of being handcuffed to a single, solitary, number. I mean....that's what they're doing now with waivers.