Y total not displayed on vertical line for last or first day of month.

My data consists of a total (Y-axis) for a given month. When making a data point graph (Layout 4 in Excel 2013), I want to display the total (Y) with the last day of the month (e.g. 1/31/13, 2/28/13, 3/31/13, etc.) as the X-axis. However, Excel doesn't have the option to use actual calendar days for a given month for the X-axis. Therefore, the Y-values do not lie directly on the vertical line above the first of the month.

Same goes if I want to use the first of the month (e.g. 1/1/13, 2/1/13, 3/1/13, etc.). Due to the irregular days for each month, the Y-values do not lie on the vertical lines.

Is there a way for Excel to use actual calendar days for the X-axis where my points will lie on the vertical line?