i have calculated the turn around time by using the formula
=(NETWORKDAYS(E151,G151,$X$187:$X$191)-1)*("18:00"-"9:00")+IF(NETWORKDAYS(G151,G151,$X$187:$X$191),MEDIAN(MOD(G151,1),"18:00","9:00"),"18:00")-MEDIAN(NETWORKDAYS(E151,E151,$X$187:$X$191)*MOD(E151,1),"18:00","9:00")
E is start date...