What is the maximum time for delivering app binary to app-store?

I had put all of my app information into itunes connect and I got an email saying it is ready for upload. Please upload app binary.

But, at the last time our client asks to change the designs of the project. I'm afraid how long the apple itunes connect will wait for upload.

I like to know,

What is the maximum time allowed by apple for delivering app binary to app-store?

is there any warning or mails will be sent to me from apple-inc about this?

You have nearly 6 months(180 days) time to upload the binary.

As per Apple developer documentation,

150 Day Warning. You will receive an email when you have had an app created for 150 days but have not yet delivered a binary, reminding you that you have 30 more days to deliver your binary or your app will be deleted from iTunes Connect. You will be given an exact date of your deadline in this email.

173 Day Warning. You will receive an email when you have had an app created for 173 days but have not yet delivered a binary, reminding you that you have 7 more days to deliver your binary or your app will be deleted from iTunes Connect. You will be given an exact date of your deadline in this email.

180 Day Deletion Confirmation. You will receive an email confirming that your app has been deleted from iTunes Connect, if you have not delivered a binary before your 180-day deadline.

It's stated under the iTunes Connect Developer Guide that:

After creating your app and it is in the state Prepare For Upload or Waiting For Upload, you have 180 days (6 months) from your creation date in iTunes Connect to deliver a binary to Apple. If you do not deliver a binary before the 180-day deadline, your app is deleted from iTunes Connect. As a result of this deletion, your app name can be used by another developer and you cannot reuse the app name, SKU or bundle ID.

All admin and technical iTunes Connect users on the developer's account will receive two warning emails as the expiration date approaches and one confirming the deletion of the App from iTunes Connect, once the 180 days deadline has been reached.

The first warning email will be sent when your App has been created for 150 days and no binary has been uploaded. The second and last warning will be sent when 173 days have passed.