YEAR Function

The YEAR function takes a DATE or DATETIME argument and returns a four-digit integer that represents the year.

The following example lists orders in which the ship_date is earlier than the beginning of the current year:
SELECT order_num, customer_num FROM orders
   WHERE year(ship_date) < YEAR(TODAY);

Similarly, because a DATE value is a simple calendar date, you cannot add or subtract a DATE value with an INTERVAL value whose last qualifier is smaller than DAY. In this case, convert the DATE value to a DATETIME value.