If you’ve held out on upgrading your iPhone or iPad over the last few years, you may need to update it and quickly—if you want to make sure it still works next week.
In a support document posted earlier this week, Apple warned users that some older iPhone and iPad models will need to have their operating system updated before Nov. 3. Without the iOS update, the devices’ GPS functions will no longer work properly, and in some cases, neither will any apps that require the correct date in time, including include web browsing, iCloud, the App Store, and calendar and email apps.
The update issue is primarily limited to GPS services on iPhones and iPads released in 2012 and earlier. (iPads with cellular capabilities from that time will also need to be updated, but GPS-only models will not.) The devices’ need for the update is due to the GPS time rollover issue that began affecting GPS-enabled products from other manufacturers on April 6, according to Apple.
But an update is also needed for iPhone 5, which was released in 2013 and has the biggest problem needing repair. Not only will GPS cease functioning without the update after Nov. 3, but neither will any services that need the correct date and time, including iCloud. It’s that last bit that could create a headache. Since iCloud won’t work after Nov. 3 without the proper update, users will have to backup and restore through their computer.
Users with affected devices need to update their device to the latest iOS it supports. This can be done on a computer or through the Settings app in iOS, and must be performed before 12 a.m. UTC on Nov. 3.
More must-read stories from Fortune:
—AT&T’s CEO appeased activist investor Elliott Management
—The wireless industry needs more airwaves, but it’s going to be costly
—Spotify’s way to convert free users to paying customers: even more freebies
—Apple looks ahead to augmented reality
—Lyft tries again with monthly memberships. Here’s how much it costs
Catch up withData Sheet, Fortune’s daily digest on the business of tech.
