These four buttons are situated at the left-hand side of the control buttons that are across the top of IQ Chart. They allow you to change the perspective and time range of the horizontal axis. The arrows pointing left "<<" move the time range displayed toward the past. This button will be grayed out when further data from the past is not available. The "Zoom In" button reduces the time range shown and effectively increases the chart size for the resulting period. The button will be grayed out when you cannot zoom in further. The "Zoom Out" button increases the time ranges and effectively decreases the chart size for the resulting period. The button will be grayed out when you cannot zoom out further. The arrows pointing right ">>" move the time range toward the present. This button will be grayed out when the horizontal axis includes the most recent data available.