title: Highlight empty cell based on multiple date comparison
body: <p>I would like to highlight the cells based on multiple dates comparison.
  There are 4 dates (D1, D2, D3, D4) on the left for different projects. which need to be compared with each month first date(M1, M2, M3... M12).</p>
  <p>so, I need to check if the cells below M1 (empty cells) falls between D1, D2 then fill red, if falls between D2,D3 fill yellow and if falls between D3,D4 then fill green. This has to be done for each cell which is below M2, M3.. M12. Each project has different time line, so I need to check for each project based on D1,D2,D3,D4 and M1,M2...mx.</p>
  <p>I tried using the conditional formatting and used &quot;Use a formulate to determine which cells to format&quot; for one cell below M1 for first project. then stretched by mouse over from left to right. It did not reflect any colour in any cell.</p>
  <p>please suggest how can i do it.</p>
  <p>Thanks
  Sbx.</p>