from lvl 3 to lvl 4 for elite buildings is 3 days
execpt for platinum weaponsmith
http://prntscr.com/8ue7uj
from lvl 4 to and from 5 to 6 is 10 days as for other elite buildings
also from level 1 to 2 is 30 min and from level 2 to 3 three hours as for other elite buildings
bug or should be on this way?