Dates can be passed as arguments for arguments used in the prepared statement. But connot be prepared in the columns section of statement.

By default, date toString returns the Java date representation so we can not use it as a valid date literal for a SQL statement.

You can create a date passing it a database connection. In that case, the toString method will return the database date function for the date object.

Let's see some examples (notice you need to use a stirng template to resolve date variable):

<script>
    var current = new Ax.sql.Date();
    
    // Setup the database type for DATE toString() representation
    current.setConnection(Ax.db);
    
    var rs = Ax.db.executeQuery(`SELECT ${current} FROM sysmaster:sysdual`);
    
    console.log(rs);
    console.log(`${current}`);
</script>

+----------+
|(constant)|
+----------+
|2019-02-11|
+----------+

MDY(2,11,2019)

<script>
    var current = new Ax.sql.Date(Ax.db);
    
    // Setup the database type for DATE toString() representation
    current.setConnection(Ax.db);

    var rs = Ax.db.executeQuery(`SELECT ${current} FROM dual`);
    
    console.log(rs);
    console.log(`${current}`);
</script>

+----------------------------+
|TO_DATE(20190211,'YYYYMMDD')|
+----------------------------+
|2019-02-11T00:00:00         |
+----------------------------+

TO_DATE(20190211, 'yyyymmdd')