Auto Fill Options list contents while filling days in Excel 2007

Enter Monday in cell A1. Change the color of the text to Red and the font to Cambria. Click cell A1 (cell A1 will have a thick border with a tiny black square at the lower right corner. This tiny black square is called the Fill handle).
Place the mouse cursor over the fill handle and drag it down till cell A7. You will see Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday entered in cells A2 to A7. You will also see the Auto Fill Options button at the lower right of cell A7. When you click the Auto Fill Options button, a list appears.
Eight options are available in the list. Depending on the data you are working, the options number change. When working with days, six options are displayed. The list options are:

• Copy Cells
• Fill Series
• Fill Formatting Only
• Fill Without Formatting
• Fill Days
• Fill Weekdays

Copy Cells – When you click this option, cells A2 to A7 will have the data Monday.
Fill Series – This option is selected by default.
Fill Formatting Only – When you click this option, cells A2 to A7 will be left blank. When you enter some data in these cells, they will have red colored text with Cambria font. This is because cell A1 has red colored text with Cambria font.
Fill Without Formatting – When you click this option, cells A2 to A7 will have Calibri, which is the default font with text color black. If you had selected a different font as the default then that font will be displayed in the cells.
Fill Days – This option performs the same operation as Fill Series i.e., filling the days Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday.
Fill Weekdays – When you click this option, cells A2 to A5 will be filled with Tuesday, Wednesday, Thursday, and Friday. Cells A6 and A7 will be filled with Monday and Tuesday.