Microsoft today announced a few deadlines for developers who have built Windows 8 and Windows Phone 8 apps. The Microsoft Store will stop accepting new apps with Windows Phone 8.x or earlier or Windows 8/8.1 packages (XAP and APPX) on October 31, 2018.

In July 2019, Microsoft will stop distributing app updates to Windows Phone 8.x or earlier, and in July 2023, Microsoft will stop distributing app updates to Windows 8/8.1 devices. At that time, Microsoft says updates will only be made available to customers using Windows 10 devices — although who knows what Windows will look like in five years.

(Don’t confuse the Microsoft Store with Microsoft’s physical retail stores. Microsoft rebranded the Windows Store as the Microsoft Store in October 2017.)

Microsoft has given Windows app developers the following timeline to help them plan:

October 31, 2018 — Microsoft will stop accepting new app submissions with Windows Phone 8.x or earlier or Windows 8/8.1 packages (XAP or APPX). This will not affect existing apps with packages targeting Windows Phone 8.x or earlier and/or Windows 8/8.1 and you can continue to submit updates until the next corresponding deadline.

July 1, 2019 — Microsoft will stop distributing app updates to Windows Phone 8.x or earlier devices.

Developers will still be able to publish updates to all apps (including those with Windows Phone 8.x or earlier packages), but these updates will only be made available to Windows 10 devices.

Developers will still be able to publish updates to all apps (including those with Windows Phone 8.x or earlier packages), but these updates will only be made available to Windows 10 devices. July 1, 2023 — Microsoft will stop distributing app updates to Windows 8/8.1 devices. Developers will still be able to publish updates to all apps (including those with Windows 8/8.1 packages), but these updates will only be made available to Windows 10 devices.

Microsoft is encouraging affected developers to port their apps to the universal Windows platform (UWP). UWP allows developers to build a single app that changes based on your device and screen size. One app can work on your Windows 10 computer, Windows 10 tablet, Windows 10 Mobile smartphone (you can skip this one), Xbox One console, and HoloLens headset.