Sunny day – got the time ?

​Look for the time-telling device on the outside back wall of the Lauterbrunnen church.
These early timepieces, when carefully built, are capable of keeping accurate time. The problem is that a sundial uses local solar time so a different sundial for every combination of latitude, longitude, and day of the year is needed.
 
A simple sundial consists only of a pin or metal rod (called a gnomon) sticking vertically out of a marked disc. The rod casts the sun's shadow onto the marked disc area of the wall.
 
Even after clocks were invented, sundials were still used to reset inaccurate clocks!