The WEEKDAY function

The following query uses the WEEKDAY function to indicate which day of the week calls are received and resolved (0 represents Sunday, 1 is Monday, and so on), and the expression columns are labeled.
Figure 1: Query
SELECT customer_num, 
   WEEKDAY (call_dtime) called, 
   WEEKDAY (res_dtime) resolved 
   FROM cust_calls
   ORDER BY resolved;
Figure 2: Query result
customer_num     called   resolved

         127          3
         110          0          0
         119          1          2
         121          3          3
         116          3          3
         106          3          3
         116          5          4
The following query uses the COUNT and WEEKDAY functions to count how many calls were received on a weekend. This kind of statement can give you an idea of customer-call patterns or indicate whether overtime pay might be required.
Figure 3: Query
SELECT COUNT(*) 
   FROM cust_calls
   WHERE WEEKDAY (call_dtime) IN (0,6);
Figure 4: Query result
(count(*))

         4