The clock your sync protocol should never trust

Edit the same note on your phone and your laptop while both are briefly offline, and eventually they have to reconcile. Something has to decide which version — or which specific changes — "wins." The obvious approach is to trust whichever device says it made the more recent edit, based on its system clock. The obvious approach is also fragile in a way that is easy to miss until it silently costs you an edit.

The problem with trusting the clock

Device clocks are not as reliable as they seem. Time zones get changed while traveling. Clocks drift out of sync over weeks without anyone noticing. Some clocks can be adjusted, accidentally or deliberately. If a sync system blindly trusts "device says 3:41pm" as ground truth, a phone with a clock that is wrong by even a few minutes can cause a genuinely newer edit to lose to an older one — or worse, cause data to silently vanish because it looked "older" than it actually was.

A logical clock instead of a wall clock

Prevon's sync protocol does not rely on raw device time to make that call. It uses a tamper-resistant logical ordering that tracks the actual sequence of edits as they happened across your devices — not what a clock claims the time was, but the real causal order: this edit happened, then that one, regardless of what either device's clock says. A phone with a wrong clock cannot cause a newer edit to be discarded, because the ordering does not depend on the clock being right.

Your phone's clock being wrong should never be the reason a note you wrote gets silently overwritten.

There is a second layer to this, too: a device never deletes a note locally just because it stops seeing it from the cloud. It only deletes something after receiving an explicit, deliberate deletion record from one of your own devices. That protects you from the scenario where a server hiccup or an attack on the sync server could otherwise look, from a device's point of view, like data quietly disappearing. A server going down should never be able to erase something only you had the authority to delete.