To illustrate the application of conditional formatting, we consider the need to highlight dates in a spreadsheet that are fast approaching or are already past.

The original spreadsheet without highlighting.

Before we apply conditional, we define any custom cell formats we may need. In this case, we have cells highlighted orange and cells highlighted yellow. We open the conditional formatting dialog and evaluate two conditions. The order is important here. In the conditional formatting dialog, once a cell evaluates TRUE, it will not be evaluated again. With that in mind, we first evaluate if a date is past due. We then evaluate if a date is fast approaching.

The modified spreadsheet with conditional formatting applied. Using this technique, the spreadsheet has become more readable and any key dates or deadlines can be more readily identified.