Users of the iPhone 6S might have noticed a bug wherein their phone’s battery percentage doesn’t update when they change time zones. Occasionally, this bug is present when you attempt to manually change the time on your device. If you’ve noticed this, take comfort in the fact that you are not alone.
Apple has noticed the bug as well, and is now offering a fix, albeit temporary, until a more permanent solution can be provided for. Currently, the best way to deal with this would be to restart your iPhone, switch to settings, select general then date & time, and turning on “set automatically.” Despite the problem existing for several months now, Apple has not offered a time frame for the fix, stating that it’s “investigating the cause and a solution” instead.