mysql 5 datetime default value

[cupboy]

What is wrong with this statement?

ALTER TABLE rec1.cd_data MODIFY COLUMN CD_DATE DATETIME DEFAULT 'NOW()';

What can I use for default value ? It seems from reading the documentation that the above should work, but it gets an error and that default cannot be applied to the table.

[FatalError]

You can't use DEFAULT when you are ALTERing a table...that doesn't make sense. 😛