TOEIC® question: She leaves on Friday?

[Guido]

Hello it's me again. As I said before I'm using 30 Days to the TOEIC Test (a Thompson Arco book) and on page 54 there is this question:
She leaves on Friday, doesn't she?

Now, why is this question in the simple present? We have been told that we use the simple present for things on a regular basis. For example, I often go the cinema.
Why is not
She is leaving on Friday, isn't she? or
She is going to leave on Friday, isn't she?

Thanks
Guido

[Alan]

You can use the Present Simple to express a future idea particularly when a specific time is mentioned. More often it's used with things like timetables: The train leaves at 8 this evening so we must hurry up. If you like, have a look at the esl lessons part on this site and look in the index for Future and you will see some notes and a short story I've written with examples of how to express the future.

Alan
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English as a Second Language
You can read my ESL story Phrasal Verbs/bring