My favorite(1) way of dealing with timezones is how Fitbit does it: They just ignore the fact that they exist! They will give you accurate minute-by-minute heart rate data for a someone, but what timezone did that occur in? Whatever one the watch was set to when it happened.

What if I live on the East Coast and fly to California and back and what to see how my body reacted to the trip? Well some times will happen twice (and get overwritten), some will never happen, and who knows when the change happened in the middle (probably when you happened to sync your Fitbit, sometime after your phone changed timezones).

(1) To complain about