iPhone 6S and 6S Plus owners may have noticed a bug relating to their battery percentage when travelling to a new time zone with their device. The bug that sometimes causes the battery percentage to not update when travelling to a different time zone, or even when manually updating the time, has now been recognised by Apple on their support page. The bug has existed since September but until now Apple had only announced they were investigating.
Details on this page also include a temporary fix if owners of the devices find their battery getting stuck until a permanent fix is available. Apple's advice in this situation is to restart the phone then go to Settings - General - Date & Time and turn on set Automatically. Apple recognises that this may not fix the issue every time and have advised users get in touch with Apple support if their battery percentage continues to stick.