IBM Watson nl-c training time
For NLC it depends on the type of data, and quantity. There is no fixed time to when it completes, but I have seen a classifier run a training session for nearly a day. 
That said, normally anywhere from 30 minutes to a couple of hours. 
Watson conversation Intents is considerably faster (minutes). But both use different models, so I would recommend to test both and see the results. Also check how each is scoring when comparing (absolute/relative).
I have a data-set that contains about 14,700 records. I wish to train it on ibm watson and currently i'm on trial version. What is the rough estimate about the time that the classifier will take to train? Each record of dataset contains a sentence and the second column contains the class-name.