TOPIC: "Please call me when you have time."

I think it is correct to say,"Please call me when you have time." Is it also English to add the article "the" before "time"?e.g."Please call me when you have the time."

In your enquiry you ask whether or not to include the article "the" in the below sentence.
"Please call me when you have time."
The best answer to this question is that, firstly there is no different in meaning between the two sentences. Secondly, they are both examples of spoken English although the sentence which includes "the" is very slightly more formal and more consistent with written English.