To change the time period of the chart, select one of the preset time period buttons from the bottom border of the chart. With these preset time periods, the end of the chart period will always be the current day or the most recent market day.
By clicking on the date range, as seen below, you can enter in custom date range using the From and To date boxes.
Or, You can also choose one of the Preset periods, such as Last Week, This Week, Last Month, This Month, Last Year and This Year, by clicking the Preset Periods button (shown below).