もう少し詳しい日程を教えていただけませんか？って英語でなんて言うの？

Using "Could you.../ Would you mind..." are polite starters to use when making requests. Its also polite to add "please" at the beginning or end of the question.

Yes, well February comprises many days and quite often with business contracts 'time is of the essence'. To be more precise you need such details as a despatch date or a despatch window during which the items will begin transit. Alternatively, you could request a 'deliver by date' so that goods will arrive to you on or before a specific date.

When you want to ask when exactly the shipment will be, then you can ask in the following ways: -Could you please provide me with a detailed schedule of the shipment? -Please provide me with the exact dates of the shipment.

The two sentences you see above are excellent ways to let your listener know that you need to know a certain date of an arrival. In the first sentence you will see the word specific and in the second sentence you will see the word fixed. Both of these words mean something is clearly determined or established. These two words would make a great addition to your vocabulary since we use these words in formal and informal settings.

A 'definite' or 'exact' date of shipment helps to show that you need certainty from the vendor. To help you get an exact date, you could provide an explanation of importance, such as needing it for the 'timely management of your business'. This puts some pressure on the vendor to be able to provide an exact date, even if they normally would not.

"Could you give me/us more information on the arrival date, please? " "Yes, what information would you like to know?" If you would like more information in general, you can simply ask for more detail about the shipment and/or the delivery date, but it's a good idea to be specific about what information or detail you would like. If you ask this right away you can avoid the vendor having extra questions for you, even though it is very polite to first ask for more information, then follow with a specific question. If you don't have a lot of time, you can ask specifically "When is the specific delivery date in February?"or "I would like an approximate date of arrival". An approximate date is even helpful, instead of specific as the vendor may not know, but the vendor can say that the "expected" or "approximate" delivery or arrival date will be between the 10th and the 17th, for example.