The "Time" field (number of weeks) listed on the description of an improvement square does not seem to be displayed correctly. Note that this is in the improvement square description (on the bottom left/center of the colony window) above the details of production output and maintenance cost, NOT the number of weeks in the Build Queue (which IS displayed properly).
On one colony, the "Time" shown was "1 wk" for all the improvements, and on another it showed "2 wks" for all the improvements. The number of weeks shown in the Build Queue was always correct.
-Proud Canadian