Amazon has a message for owners of pre-2012 Kindle tablets: Adapt or die.
"Adapt" in this case means that users who have had their Kindle for more than four years—and haven't connected to Wi-Fi since October 2015—need to update their device's software by tomorrow, March 22, or risk losing access to the Internet (that means no more romance novels for you, Mom).
Those who don't make the "critical" update will receive an error message reading: "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."
Users can easily make sure their old Kindles are updated by connecting to Wi-Fi and letting the cloud do its magic. But users who fail to do so by Tuesday will lose access until they update the old-fashioned way, by actually plugging the Kindle into their computer.
Here's a handy chart to see if you need to update your device.