making a schedule with auto time format and adding total hours

looking to make this schedule work a little easier. how can i make it to where all i do is type in 8 on the in box and 5 in the outbox so it says 8:00 5:00 and then add the lunch time in the same way but the tricky part is to make the totals box add all the times for the week and subtract the lunch time which is always an hour

thanks
i attached the file