Free Planet returns - GPS watches always give you - the correct local time.
|where, but not when|
"We already have GPS-watches, Mike, ya dumb-ass!" and you'd be right. You'd be impolite, and (hence) a little bit off-topic, but you'd be right.
We do already have GPS-enabled watches, but we only use half the functionality of them. We know where we are but not really when we are.
Well, let's put it like this, "The Sun crosses the sky all day, every day," and we always know the path for any given set of GPS coordinates. We have tables of the Sun's path across the sky at any date in the future. Even with Earth's seasonal wobble, we can always find the noon-point. That's the highest point in the sky the sun will achieve for any given day in the next few hundred years.
This is The Real Time - and it's local to where you are on the planet, or should be.
"But we already have this, Mike, ya dumb-ass!" and again, you'd be right. But you're wrong. We have fixed, geographical and arbitrary hour-slices through the Sun's path i.e. Time Zones, centred around Greenwich UK. A disgusting throw-back to the Good Old Maritime Daze of the British Empire and the East India Company. Sarcasm engine disengaged.
What Free Planet needs is, "To know the time NOW where I'm stood," if we used GPS-watches to a) find where we are and b) tell us the noon-relative time, it'd be better for us all.
But now, "We tell time by the ticking of Caesium atoms, Mike, ya dumb-ass!" to which I say gravitational fluctuation via altitude or geology.