I have some Call stats that I need assistance with. I need to calculate the
length of time a call has been open for, within an 10 working hour day.

Current Data: 4 columns with the following:-

CREATE DATE - in dd/mm/yyy Format
CREATE TIME - in HH:mm:ss
RESOLVED DATE - dd/mm/yyyy
RESOLVED TIME 0 HH:mm:ss

Goal: To calculate the diiference between the create time and reslove time.
If a call has been open for more than a day, then 10 hours will need to be
added to the total (we are measured on 10 working hours each day). If the
call has been open for 2 days, then its 20 hours and so on....

If some can assist here I would greatly appreciate it.

Thanks