Question

I just want to know if it is possible for a a certain cell to be highlighted based on date whenever I put notes into another cell? As you can see at the image below, there are set of calendar with dates.

Now what I want to achieve is to highlight those dates whenever I put notes into another cell as the image shown below

Let’s say I input a note in 5-Jan, Saturday the cell in image 1 ( January 5 ) will be highlighted with background color

Answer 1

Your problem consists of two parts. First you need to know how to use conditional formatting based on a formula, then you need to map your calendar cells to the corresponding notes cells.

Conditional formatting based on a formula is documented on several places on the web, for example here. For your case, I have created a screenshot of a simple example:

The difficult part (or hard labour, depending on which route you choose) in your case is to map all cells in your calendar to the corresponding cells potentially containing the note. So you need a way to calculate which day in the year a particular cell is.

I think you could achieve that via 12 different conditional formatting formulas, where you refer to the contents of “this” cell using INDIRECT("RC",FALSE) to get the day of the month, and then add the number of days before that month (for which you need 11 different constants). That result can be used as the index into your array of potential notes. So for February, the formula to calculate the day of the year becomes:

31+INDIRECT("RC",FALSE)

Using that number to check the row in your notes column (let’s say they are in column A), the conditional formula for all cells in February becomes

=NOT(ISBLANK(INDIRECT("A"&(31+INDIRECT("RC",FALSE)))))

Then do the same thing for each month, where the constant (like 31) is different for each of them.

Note that using "RC" in INDIRECT() like this only makes sense in a conditional formatting formula.