Source: US. Bureau of the Census
Release: New Residential Sales
This is the median number of months for sale since the completion of the home.
US. Bureau of the Census, Median Number of Months on Sales Market for Newly Completed Homes [MNMFS], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/MNMFS, December 7, 2016.