Outdated example: https://github.com/atuttle/Taffy/blob/master/examples/api_callback/resources/dateCollectionCallback.cfc
This example is written as if the callback function is called on each column of each row of the source query individually, which is no longer true. To be honest, I'm not sure if it ever was! 😉
Please read the documentation for queryToArray and update the example code accordingly.