Benchmark 11C
Common Themes: Constancy and Change
Grades 6-8, page 274

Things that change in cycles, such as the seasons or body temperature, can be described by their cycle length or frequency, what the highest and lowest values are, and when they occur. Different cycles range from many thousands of years down to less than a billionth of a second.
 

See the general discussion in Unifying Concepts and Processes: Constancy, change, and measurement.