Can I use Apple Watch when the device is in Airplane Mode and not receiving or sending wireless data? For example, to use the clock and fitness tracking, can I turn off wireless and still use the device? (For those interested, if I can avoid it, I’d rather not expose my wrist or body to a Radiofrequency Electromagnetic Field, a Group 2B Possible Carcinogen, as described by World Health Organization / International Agency for Research on Cancer.)