Collect data at uniform time intervals. The data is recorded and can be used for analysis. The frequency of data collection will depend on the type of analysis that is being conducted. For example, river water levels on the first day of June would only require data to be collected each year on June 1. Alternatively, to track the daily closing price of a stock market index, the final value of each trading day would need to be recorded. The time or date the data was recorded, as well as the data value, should be documented.
List the data chronologically, with the first or earliest data point listed first, and the most recent data point listed last.
Construct a graph to view trends over time. Use a spreadsheet program to graph the data, using "Time" as the X-axis and the data values as the Y-axis. Since the data is listed in chronological order, earliest to latest, the graph will display the movement of values from past to current moving from left to right. A scatter chart with the points connected or a line chart are common ways to display time series data.
Fine tune the graph to your individual needs. The data can also be used for further analysis. Forecasts can be made based on current trends in the data, or average values or seasonally adjusted values can be attained.