Weeks are numbered using the ISO convention
If you want to change the start date, type the new date into cell D3. The ribbon
calendar will automatically update.
If you want to add more items to the list, select the entire row by clicking the
ROW NUMBER as designated (row 18 , where it says "select this entire row").
Right-click and choose INSERT from the menu. If it says "Insert Cells" or something
like that you have to clear the currect selection by hitting the ESC key.
To add more columns, you will need to extend the date information in row 6,