Where am I?!

1) Latitude
2) Longitude

Latitude is easy to exactly find out.
Calculating latitude, tropic of cancer and equator
α is exact same degree of sun shadow

Longitude is completely arbitrary

How to keep the time?
-Need Periodicity

We need chronometer
-periodic, isochronous, predictable

Equilibrium
c = 2πr
2πradians = 360°

cos(3π/4)=-0.707
Sin(3π/4)=0.707

Angular Velocity w
ΔΘ=ωt