https://arstechnica.com/gadgets/2017/12/ios-11-2-fixes-date-bug-that-crashes-idevices-begins-apple-pay-cash-rollout/

Some iPhone users woke up this weekend to continuously crashing iPhones, iPads, and other iDevices, and Apple has pushed out its iOS 11.2 software update early to fix this and numerous other issues. The update also starts the rollout for Apple Pay Cash and enables 7.5W wireless charging on new iPhones.