The HOUR function returns the hour part of a value. The argument must be a time, timestamp, or a valid character string representation of a time or timestamp that is neither a CLOB nor a LONG VARCHAR. The result of the function is a large integer. If the argument can be null, the result can be null; if the argument is null, the result is the null value.
HOUR ( expression )
Select all the classes that start in the afternoon from a table called TABLE1.
SELECT * FROM TABLE1 WHERE HOUR(STARTING) BETWEEN 12 AND 17