If you're in the UK, just use the MSF radio signal to sync your clock [1].

> The end result exactly matched my expectations—the best criterion for success that I can think of. With an LLM providing the heavy code lifting and the CAD work, I think I spent more time waiting on supplies to arrive than on anything else—something attributable to my lack of planning and the ease of next-day delivery.

I think the author robbed themselves of a deeper understanding.

[1] https://www.npl.co.uk/products-services/time-frequency/msf-r...