Smartphone users holding on to the bygone era of the Steve Jobs iPhone may be locked out of several apps Sunday if they don’t upgrade the software.

Some iPhone 5 devices, the last of Apple’s iPhones to be overseen by Jobs, need to be updated to iOS version number 10.3.4, the company said in a news release Saturday. Without the update, apps that rely on accurate date and time will not work, including the App Store, iCloud, email, and web browsing. The company said that the issue is with “GPS time rollover,” in which GPS-based products reset the clock.

Users who don’t upgrade their iPhone 5 -- and other Apple devices released in 2012 and earlier -- will experience issues with those apps beginning “just before” midnight this Saturday.

Many users over the years have been apprehensive to upgrade iPhones with older batteries because of performance issues, some even claiming that the company was intentionally slowing older phones to encourage new purchases. The company denied the claims amid U.S. government inquiries into the issue in 2018.

"We have never -- and would never -- do anything to intentionally shorten the life of any Apple product, or degrade the user experience to drive customer upgrades," Apple said at the time.

In the weekend news release, Apple reinforced the need to keep its devices up to date. “It's always a good idea to keep the operating system on your iPhone updated,” it said. “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.”