How To: Change symbology for point data based on a date field within an attribute table
When intending to change the color, size, or shape of a point feature layer based on dates within the attribute table, a tracking layer must be configured using the ArcGIS Tracking Analyst extension.
Note: Tracking Analyst allows the symbolization of temporal data using time windows and other specialized options for viewing data that changes through time.
The instructions provided describe how to configure a tracking layer that updates the color of the symbology, based on a date field in the feature class' attribute table. In this example, the field contains system-formatted dates.
- Create a feature class that contains a date field. For more details, refer to the following help page: About creating feature classes.
- Enable the Tracking Analyst extension by navigating to Customize > Extensions, and check the check box next to Tracking Analyst.
- Add the Tracking Analyst toolbar to ArcMap by navigating to Customize > Toolbars > Tracking Analyst.
- In an editing session, create data to populate the date field. For more information, refer to the following help page: Fundamentals of date fields.
- Click the Add Temporal Data button on the Tracking Analyst toolbar to open the Add Temporal Data Wizard dialog box.
- For Storage policy:, select Refer to data on disk (no separate copy).
- Specify the data source as the feature class created in Step 1 that contains the now populated date field.
- Ensure that Field containing the date/time: is selected correctly, based on the written format of the date.
- Click Next > Finish. This creates the tracking event layer.
- Double-click the tracking event layer to open the Layer Properties dialog box.
- Go to the Symbology tab.
- Under Events in the Show: panel, check the check box next to Time Window.
- Specify the desired Time Window.
- In the Drawn As: (choose one) panel, select Color.
- Specify the desired number of classes using the Past option.
- Set the range by starting at the highest number and enter the desired range, and continue down to the lowest class.
- Click OK.
- Save the map document. At this point, changes made to the feature class created in Step 1 are reflected in the map document with the tracking layer when it is opened.
- ArcGIS Help: Symbolizing data in a time window by color
- ArcGIS Help: Temporal data symbology
- ArcGIS Help: Fundamentals of date fields