Your iPhone is now as accurate as Apple Watch!

[Brian Garrett]

iPhones now have millisecond accuracy at all times as of iOS 8.2.

http://watch.camp/2015/03/apple-watch-timekeeping-accuracy-iphone/

[Oregonian Haruspex]

Post by Brian Garrett
iPhones now have millisecond accuracy at all times as of iOS 8.2.
http://watch.camp/2015/03/apple-watch-timekeeping-accuracy-iphone/

This is only true as long as your iPhone is in contact with the
internet. If you engage airplane mode you will find that it drifts,
and the last one I checked drifted more than my old railroading pocket
watch.