Calculate elapsed time in days,hours and minutes excluding weekends and holidays

Hi, I understand that networkdays takes care of the weekends but the thing is there are also times when deliveries are made on a weekends like in January where all weekends have deliveries too. I want to make the worksheet flexible by indicating weekend dates that have deliveries to be included in the count of working days. I have included in the results sheet the expected results based on start and end dates/times. Perhaps another list that will show which weekends should be included in the workdays count or is there another workaround for that?