> I think devices that need a longer life should keep track of the last seen timestamp, then they can detect a rollover. The device would keep a local rollover

> I think devices that need a longer life should keep track of the last seen timestamp, then they can detect a rollover. The device would keep a local rollover counter and just add 20 years per count. This should stay correct until that counter rolls over, or if the device is offline for >20 years. Better in some ways, worse in others. Can still result in unexpected behavior if configuration memory is lost. And if it ever accepts an invalid future time for whatever reason, it gets "stuck" in that failure state.