Seems to me the most obvious answer is to return to sundials, no?
Only works during the day? Which, come to think of it, I'm not entirely clear how humans kept time at night long ago. I'm assuming they learned roughly where some constellations were?
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Only works during the day? Which, come to think of it, I'm not entirely clear how humans kept time at night long ago. I'm assuming they learned roughly where some constellations were?