You can scroll backward and forward in time using the Scroll back and Scroll forward buttons on the Time Slider window. These buttons are not available when the time extent of the time slider, which is defined by the Start time and End time values, is set to the full time extent. However, when you modify Start time and End time of the time slider such that you are focusing on a time extent that is less than the full time extent of the time slider, the Scroll back and Scroll forward buttons are made available.
Clicking these buttons allows you to scroll backward and forward to a time extent that lies within the full time extent of the time slider. This can be thought of as panning across the timeline. For example, if the full time extent is from January 1 to January 10, you can modify the start time and end time of the time slider to be from January 3 to January 7 to focus on just five days that are of interest to you. If the time step interval is set to 1 day on the time slider, clicking the Scroll back button once will allow you to visualize the data from January 2 to January 6. Clicking the Scroll back button again will allow you to visualize data from January 1 to January 5.
Learn more about modifying the start and end time of the time slider