No computer is totally free from all software bugs; even minor changes to code can cause small issues that annoy and confuse users. The iPhone has encountered many bugs like this, including several related to time zone and rapid battery drain. Patches and software updates usually resolve these problems quickly, but if you’re suffering through them, the wait between updates can feel excruciating.
This weekend, Apple released a support document for the iPhone 6s and 6s Plus, detailing a bug where the battery percentage indicator stops updating without warning. This results in users thinking they have more power left in their batteries than they actually do.
The bug seems to stem from jumping time zones, whether from manual shifts to the clock, or changes caused by entering a different time zone. Restarting the phone should cause the indicator to begin updating again, and if your device’s time is set to automatically update based on location, you reportedly shouldn’t run into this problem.
Apple is working on a fix for the bug and the company’s next iOS 9 software release will reportedly solve this issue.