Dear Sir,Hi Shabbo,
please check the attachment, I tried to solve your problem, hope it'll help you,
Step 1. Convert Time Format
Step 2. Merge Date and Time using , Text(G4,"DD/MMM/YYYY")&" "&Text(H4,"HH:MM:SS")
Step 3. Find out difference of time using , IF(F5="Saturday","",IF(F5="Sunday","",IF(F5="Monday","",I5-I4)))