Or it can set the clock locally from the particular app instance used for the initial setup.

If that's not accurate enough due to drift, then it can also rejigger the clock during subsequent runs of the app.

And that's probably good enough.

It's just a robo-vac -- nobody is going to be late for work or even annoyed if it drifts a bit and a sequence starts at 7:02:37 instead of 7:00:00.