trying to calculate the # of hours for an SLA hours that excludes hours closed

trying to calculate the # of hours for an SLA hours that excludes hours closed
So if an order comes into the system during closed hours of 9:00 pm and 5:00 am how long did it really take the store to start the order.
Example
The start time to work orders is 5:00 am the end time is 9:00 pm or 21:00 hrs
The order came in at Feb 10, 2020 3:40:30 PM
The worker started the order Feb 11, 2020 7:38:12 AM
so how would you write the formula to say it took x number of hours from the time the order came into the system until the worker started the order excluding the closed hours?

Hi eblue,

Assuming you operate always from 5am to 9pm (7 days a week):

Try: =((B9*24)-(A9*24))-(8*DAYS(B9,A9))

A9 = The time the order arrived
B9 = the date/time the worker starts to process the order
The first part simply calculates the hours between the two dates/times. The second part calculates the days between the two dates and subtracts 8 hours per day, being the hours between 9pm and 5am when the store is closed.
I have tested on a number of scenario and it seems to give the correct hours.
Let me know if that works/does not work.

I'm sorry but that did not work I need the value in hours and the above formula when I try it using my real date it gives me a #value error.

Hi eblue,
Formula works for me. See attached file. Maybe there are more variables to consider.
Maybe you could upload a sample file with your date and expected outcome.