|Here is another option, |
With your Column Headings in Row 1 as Text Strings,
that spell out the complete month like this:
A B C D E F G
1) January February March April May June July
1) Select your range of cells A1:L5000
2) On the ribbon click Conditional Formatting
3) Click on New Rules, it’s near the bottom of the dialog box.
4) Click Use Formula to determine which cells to format.
5) Enter the formula:
6) Click on the Format button
7) Select the Fill Tab
8) Select a pretty color
9) Click OK
10) Click OK
I would strongly advise against selecting Whole Columns.
Do you really need to CF over 12 MILLION cells??
Select a reasonable range and use that, I have used 5000