Working Hours Calculation

Hi
I am in need of some help please. I need to work out the number of working hours between various start and finish dates/times. Working hours are 7am to 11pm Monday to Saturday, and 8am to 4pm on Sunday. I can work out the total number of hours between two dates and times with no problem but this provides a false picture of the actual number of working hours used (examples in attached). Is there a way to work out the actual working hours (column D in attached) automatically?
Thanks

Clean all exptected results in column D.

D2

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That's amazing, thank you so much. Is there a simple way to make this show the result in hours and minutes?

D2

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