Here is a scenario: A running total of numbers, updated daily. You want to capture the previous day’s total, as you can see in the picture below.

I’m showing the answer in two steps here, in real life I’d make it into one formula.
The first step is to capture the row number of the previous day’s total. Finding it using the numbers in Column C would be way too complicated. But Column B has the kind of data we can use.
Using the formula =LOOKUP(2,1/(B2:B29<>0),ROW(B:B)) captures the row.

What the lookup formula is doing is starting by evaluating the numbers from B2:B29 looking for values that aren’t equal to zero.
This creates an array like this: {TRUE;TRUE;TRUE;TRUE;TRUE;TRUE;TRUE;TRUE;TRUE;TRUE;TRUE;TRUE;TRUE;TRUE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE}
The TRUE values will equal 1 and the FALSE values equal 0.
This means when the formula divides 1 by those values, an array looking like this is created:
{1;1;1;1;1;1;1;1;1;1;1;1;1;1;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!;#DIV/0!}
Lookup can’t find 2 in the array, so it settles for the largest value in the array that is less than or equal to lookup_value.The ROW function tells it to return the row number from the array B2:B29.
The second step is to combine the row number with the column number and show the result using =INDIRECT("C"&D2)
And there you have it. A quick way of always finding the previous day (month, year, whatever).

Passing a spreadsheet around between organizations has a hidden problem; one that can easily make trouble. And the trouble comes, not from the spreadsheet, but from the default date setting on the computer.

Excel uses the default date setting to interpret the order of date information. Whether its’ Month-Day-Year or Day-Month-Year, or even Year-Month-Day, that information comes from the OS date settings. These are settings that we don’t often think about once we’ve set them. And typically, they are the same throughout an organization.

But take the spreadsheet you’ve designed, that uses Month-Day-Year into a Day-Month-Year organization, and all sorts of problems crop up.

The first problem is that you might not notice immediately; if July 6, turns into June 7 – that might not jump out at you as a problem. If you are lucky, you’ll spot something weird about the 12th of Month 21 …

So how do you nail down those dates so they can’t shift? One strategy is to break up your date entry into your preferred format, and then rebuild the date using the DATE function.

The syntax for the DATE function is =DATE(year, month, day)

Here you can see the DATE function is building a date from the values in three separate cells: A3, B3 and C3 and the formula looks like this =DATE($C3,$B3,$A3)

Another advantage of this strategy is that Data Validation can be applied to these cells; ie the day column can be restricted to whole numbers between 1 and 31, the month column to whole numbers between 1 and 12 and the year column as well. In the sample file I’m using, the column holding the complete date (D) is hidden from the user. They will only see columns A thru C. The complete (and correct) date is referenced in formulas.

An alternate strategy would be to use the DATE function to extract the correct order from a whole date typed into a cell. In this case you would need to rely on the users to enter the date consistently regardless of their date system. I would recommend a custom date format be applied and a comment to tell the user what the required date format is. Breaking the date up avoids this reliance on the user’s compliance.

In a previous post, I discussed making a Button Bar Chart. That whole process really inspired me to think about simplified charts for presentations.

Which got me thinking about Waffle Charts.

Waffle charts are excellent for looking at data sets where the smallest numbers are the important ones. You can use colour (as I have above) to make those numbers stand out.

But oddly, I don’t see people using a lot of waffle charts in their presentations. And there is no template for a waffle chart in Excel.

You can find some interesting ideas about building Excel waffle charts for dashboard purposes and I recommend this article to you: Interactive Waffle Charts in Excel

However, I was looking for something different. Something that wouldn’t have me counting and colouring cells manually (shudder).

Building the Waffle

I chose to build the waffle chart using a series of conditional formatting rules. The first step was creating the formula to count the cells of the waffle.

In case the picture is a bit small, the formula used here is:
=(MOD(ROW()+8,10)*10)+(COLUMN()-2)+1

This uses the row and column position of the cell to count from 1 to 100 in a 10 by 10 grid.

I then built on that base formula with this monster formula:

The formula checks the position number of the cell generated by the base formula and sees if it is less than or equal to the number of values in each category in column A. It then returns the value of the category in each cell.

Because I wanted to put symbols in the cell like these examples.

I took that monster formula and made it into a named formula.

This made building the conditional formatting rules much easier to do(simply because the conditional formatting dialog is so cramped).

Lastly, I built a series of conditional formatting rules to change the background colour of the cell based on the value returned by the formula. For the waffles using symbols, the rule formats the colour of the font, instead of the background.

A couple of additional pointers

To create a perfect grid, switch the view in Excel to Page Layout View. Page Layout View uses the same measurement scale for both row height and column width. Set your measurements here.

For the symbol waffles, use the File> Options>Advanced> Display Options for this worksheetand turn off the display of gridlines. That way when you copy the waffle, the gridlines will be invisible.

This post is originally from 2018. If you want help with the newest and classic features in Excel & PowerPoint drop me a line at catharine@mytechgenie.ca