Synchronizing cameras and audio during shoots, we came up with a method to reliably sync devices clocks. As Apple doesn’t actually allow apps to change the system clock’s behavior, we came up with our own NTP syncing implementation using algorithms described here and here.

As a short rundown, we send a total of 300 packets via the MultiPeer Connectivity framework and use these to gather a mean deviation betweenboth devices. This is stored locally on the device that initiated the sync, allowing for multiple devices to sync to one “master” device/time.

Please note that syncing has to happen one device at a time due to the nature of how our framework handles the packet exchange. We may add batch syncing at a later time.