If you have an older Kindle e-reader, you may need to update its software before tomorrow in order to continue to download books from the Cloud, access the Kindle Store and use other Kindle services. Otherwise, Amazon says you may get an unhappy error message like this: Your Kindle is unable to connect at this time. Please make sure you are within wireless range and try again. If the problem persists, please restart your Kindle from the Menu in Settings and try again.
If you have a Kindle and need more info and/or update instructions, click HERE.