Warning from Apple for iPhone 5 owners

https://support.apple.com/en-us/HT210712

Update your iPhone 5 to continue using App Store, iCloud, email, web, and other services

Starting just before 12:00 a.m. UTC on November 3, 2019,* iPhone 5 will require an iOS update to maintain accurate GPS location and to continue to use functions that rely on correct date and time including App Store, iCloud, email, and web browsing. This is due to the GPS time rollover issue that began affecting GPS-enabled products from other manufacturers on April 6, 2019. Affected Apple devices are not impacted until just before 12:00 a.m. UTC on November 3, 2019.

Update your device's software

It's always a good idea to keep the operating system on your iPhone updated. If you have an iPhone 5, it's especially important to update your device's software wirelessly or using your computer before November 3 to maintain accurate GPS location and to continue to use functions that rely on correct date and time including App Store, iCloud, email, and web browsing.

If the update to iPhone 5 is not completed by November 3, 2019, you will be required to back up and restore using a Mac or PC in order to update because over-the-air software updates and iCloud Backup will not work.

Check your device's iOS version

After you update your iPhone 5, you can check to make sure that your device has updated successfully:

Open the Settings app.
Tap General, then tap About.
Look for the number next to Software Version.

The updated software version number should be 10.3.4.