Elapsed working hours, without counting weekends or non-working hours

Hi Excel wizzes,

Amazing resource you have here on this forum.

I was hoping someone could assist me with calculating elapsed hours - taking into consideration working hours and (non-working) weekends.

Please see the example spreadsheet attached. I was trying to use a formula provided in a similar post, which works perfectly over weekends but doesn't work over non-working hours.

Thank you very much.

PS, I hope this works as I have never used a forum before!