Summer, the season of the year occurring between spring and autumn. Astronomically, summer in the Northern Hemisphere lasts from about June 21 to September 23; in the Southern Hemisphere, from about December 22 to March 21.
Sundial, a device used to tell time by the sun. Nearly every sundial has two basic parts: a pointer, called a style or gnomon, which casts a shadow; and a numbered dial on which the shadow falls to show the hour. See more »
A light year is a way of measuring distance. That doesn't make much sense because "light year" contains the word "year," which is normally a unit of time. Even so, light years measure distance. See more »