Days on market is how long a house has been listed for sale without going under contract, counted from the day it was listed. Buyers and agents read a high number as a sign the house is overpriced or has a problem, and offers tend to shrink the longer it sits. The count resets when a listing is withdrawn and relisted, which some agents use to hide a stale listing.
Why it matters
A house that sits too long on the market usually needs a price cut to get moving again.