Today is Friday the 13th. If you are a raging friggatriskaidekaphobiac, I suggest you to stop reading this post. For the rest of you, I have something fun.
Given a year in cell C3, let’s find out all the months with Friday the 13th. Something like this:
[Related: Finding next Friday the 13th using formulas]
Finding all Friday the 13ths in a year
Here is a formula to find the first Friday the 13th in a year.
{=IFERROR(SMALL(IF(WEEKDAY(DATE($C$3,ROW($A$1:$A$12),13))=6,ROW($A$1:$A$12)),1),””)}
Let’s understand how it works, going from inside out:
DATE($C$3,ROW($A$1:$A$12),13) portion: This generates an array of 12 dates, one for each 13th of the month in the year C3.
WEEKDAY(DATE(…))=6 portion: This checks how many of those dates are Fridays. Returns an array of TRUE / FALSE values.
IF(WEEKDAY(DATE(…))=6,ROW($A$1:$A$12)) portion: This returns an array of month numbers where we have Friday the 13th and FALSE values.
SMALL(IF(…),1) portion: This will give us the first month (ie 1st smallest value) with Friday the 13th in the year C3.
IFERROR() to suppress any errors.
To show all the Friday the 13ths in a year, simply replace 1 with an array of numbers (up to 3 should do).
Download Friday the 13th finder workbook
Click here to download Friday the 13th finder workbook. Enter a year in cell C3 and see all the months with Friday the 13th instantly.
A challenge for you…
If you are still reading, I have a challenge for you. Can you write a formula to find the next year with three Friday the 13ths? Assume the year is in C3. Post your formulas / VBA in the comment section.
hint: in the downloadable workbook, you can find an answer for this.
So that’s all for now. Enjoy your Friday the 13th.
9 Responses to “Show forecast values in a different color with this simple trick [charting]”
While this works in a pinch, it clearly "lightens" the colors of the entire chart. Depending on where you use this, it will be blatantly obvious that you don't know what you are doing and present a poor looking graph.
Why not separate the data into different segments when charting and have as many colors as you have data points? You might have to create a new legend and/or repeat the chart in "invisible ink", but it would be cleaner and more consistent when new or updated data becomes available.
While I think I agree that doing it "properly" via a second series is preferable, I don't necessarily agree that making the entirety of the "future" (data, gridlines, and even the axis) semi-transparent is "poor looking". I think it could be seen as adding more emphasis to the "future-ness" of the forecast data.
In short, it's another tool for the toolbox, even if it's never needed.
Simply and clever 🙂
Quick & effective, cool. thanks.
I always use the dummy series.
Nice little trick, thanks very much!
Two sets of data better. Control is much better.
You can use the same chart next month to see what is actual and what is forecast.
To use this trick, I think grid lines has to be removed, that will make the graphic much more sharp.
to be honest, i dont understand why there is needed to do this way... in this case horizontal lines will be pale as well. then why a just can't change the color of the line partly???
Great tutorial. Thanks for the tutorial!