Excel Fill Options
You probably already know that you can fill a series of Excel cells by entering the first two numbers in a series and then select the two cells and drag on the marker in the bottom right corner of the selection. Excel fills the selected cells with the next numbers in the series. to find more fill options, including the ability to copy the series rather than filling it, select the cells but use the right mouse button to do the dragging. If you're filling dates you'll get options like Fill Weekdays and Fill Months - that let you control the fill series that Excel creates for you.