Hours between two date time formula showing negative values in Salesforce

I have written a formula to calculate the difference between two Date/Time fields,
Please find the formula

`ROUND(24*(
(5*FLOOR((DATEVALUE(First_Response__c)-DATE(1996,01,01))/7) +
MIN(5,
MOD(DATEVALUE(First_Response__c)-DATE(1996,01,01), 7) +
MIN(1, 24/24*(MOD(First_Response__c-DATETIMEVALUE('1996-01-01 12:00:00'), 1)))
))
-
(5*FLOOR((DATEVALUE(CreatedDate)-DATE(1996,01,01))/7) +
MIN(5,
MOD(DATEVALUE(CreatedDate)-DATE(1996,01,01), 7) +
MIN(1, 24/24*(MOD(CreatedDate-DATETIMEVALUE('1996-01-01 12:00:00'), 1)))
))
), 2)

Here I have a case whose created date is 12/12/2016 2:16AM and Firstresponse date is 12/12/2016 10:54 AM now the case response hour formula field shows me the difference between the above as -15.37 .

I tried to calculate the difference between two date Time for 24 hours not for a business hours, I only want to exclude weekends,

The hour calculation should be from 12:00 AM today to 11:59 PM the next day.

Please advise