In many versions of Excel, you can use a Microsoft date picker control to create an Excel date drop-down in a cell. Unfortunately, this won't work in 64-bit versions of the popular spreadsheet ...

If your cells contain data, the sample displays the first date in your range of selected cells. Click "OK" to apply your formatting. Press "Ctrl-C" to copy the cells you formatted.

Use Microsoft Excel's TODAY() function in simple expressions to highlight the current date and past and future dates.