Explanation
The QUARTILE function is automatic, and will calculate the 1st quartile with an input of 1, the 2nd quartile with an input of 2, and the 3rd quartile with an input of 3. With an input of 0, quartile returns the minimum value in the data.
The trick in this case is to arrange the conditional formatting rules so that they run in the same direction. The first rule highlights values greater than the 3rd quartile. The second rule highlights values greater than the 2nd quartile, the 3rd rule highlights data greater than the 1st quartile, and the last rule highlights data greater than the minimum value.
Explanation
The AND function takes multiple arguments and returns TRUE only when all arguments return TRUE. The DATE function creates a proper Excel date with given year, month, and day values. Because the reference to B4 is fully relative, it will update as the rule is applied to each cell in the range, and any dates that are both greater than 8/1/2015 and less than 11/1/2015 will be highlighted.
Use other cells for input
You don’t need to hard-code the dates into the rule. To make a more flexible rule, you can use other cells like variables in the formula. For example, you can name cell E2 “start” and cell G2 “end”, then rewrite the formula like so:
=AND(B4>=start,B4<=end)
When you change either date, the conditional formatting rule will respond instantly. By using other cells for input, and naming them as named ranges, you make the conditional formatting interactive and the formula is simpler and easier to read.
