The time zone of the device is determined by the time zone in your phone settings when binding. In other words, if you are in Beijing time zone of China, but your phone is set to the time zone of the United States, then after you bind the device, the time zone of the device is the time zone of the United States. Even if you change the time zone in the mobile phone settings after the distribution network, the time zone of the device will not change, unless you remove the device and add it again,