You can try it out here: https://duckling.wit.ai/
The install instructions are on their github page. It takes a while to compile. https://github.com/facebook/duckling/ To run duckling you start a webservice
stack exec duckling-example-exe
Afterwards you can add duckling to your pipeline. There are some clues here: http://forum.rasa.com/t/how-to-use-duckling-in-pipeline/91/6