anchor.diff:  FROM DUAL;
   ```
   
  -* This statement calculates how long do buyers have to wait. 
  +* This statement calculates how long buyers have to wait. 
   +
   ```
   SELECT id, DATEDIFF( DAY, order_date, delivery_date ), price 
  
positive.code: * `datepart`
  +
  is YEAR, MONTH, DAY, HOUR, MINUTE, SECOND, QUARTER, WEEK, or one of the
  following abbreviations, should be enclosed in quotation marks:
  +
  [cols="15%,85%"]
  |===
  
negative.code: 
  ** For seconds, the maximum number is equivalent to approximately 68 years. 
  
  ** For weeks, the dates must be later than 0001-01-07.
  
  <<<
  [[examples_of_datediff]]
  