SQL DateDiff advanced usage?

Question

I need to calculate the DateDiff (hours) between two dates, but only during business-hours (8:30 - 16:00, no weekends). This result will then be put into the Reaction_Time c

Answer 1

Use this code : to find out weekend in between dates

 (
    DATEDIFF(dd, open_date, zassignment_date) + 1 
    - ( (DATEDIFF(dd, open_date, zassignment_date) + 1) 
    -(DATEDIFF(wk, open_date, zassignment_date) * 2) 
    -(CASE WHEN DATENAME(dw,  open_date) = 'Sunday' THEN 1 ELSE 0 END) 
    -(CASE WHEN DATENAME(dw, zassignment_date) = 'Saturday' THEN 1 ELSE 0 END) )) wk_end