Fibonacci Time Zones
An indicator used by technical traders to identify periods in which the price of an asset will experience a significant amount of movement. This charting technique consists of a series of vertical lines that correspond to the sequence of numbers known as Fibonacci numbers (1, 2, 3, 5, 8, 13, 21, 34, etc.). Once a trader chooses a starting position (most commonly following a major move) on the chart, a vertical line is placed on every subsequent day that corresponds to the position in the Fibonacci number sequence. 
Investopedia Commentary
Fibonacci numbers are a sequence of numbers where each successive number is the sum of the two previous numbers. For reasons unknown, these numbers play an important role in determining relative areas where the prices of financial assets experience large price moves or change direction. The four popular Fibonacci studies are arcs, fans, retracements and time zones.
Related Links
Fibonacci And The Golden Ratio
High-Tech Fibonacci
See also: Chartist, Fibonacci Arc, Fibonacci Fan, Fibonacci Numbers/Lines, Fibonacci Retracement, Indicator, Retracement, Technical Analysis
Also spelled: Fibonaci time zones, Fibonacci time zone, Fibonacci Time Series, Fibonacci timezone