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.
8 Responses to “Introducing PHD Sparkline Maker – Dead Simple way to Create Excel Sparklines”
This looks like it could be very useful for a project I'm putting together right now, thank you so much. Quick & silly question, how do I copy & paste the sparkline as a picture?
Question answered. For anyone else:
Select chart>Hold Shift key & select Edit/Copy Picture>Paste
[...] more information about PHD Sparkline Maker, please read this article and to learn more about Sparklines, read this article from Microsoft Excel 2010 blog. Also there [...]
Am I right in thinking that the y-axis is set automatically by excel?
That makes it possible to get the column chart not to start at zero.
Andy - yes, it is currently set to 'auto', which defaults to a zero base for positive values, but you can change that by left-clicking the chart, then choosing (in Excel 2007):
"Chart Tools/Layout/Axes/Primary Vertical Axis/More Primary Vertical Axis Options"
PUBLIC SERVICE ANNOUNCEMENT: When manually editing a chart's minimum/maximum axis values, PLEASE be sure there's a valid reason and that doing so won't skew the message shown by the data (e.g. by exaggerating differences). If in doubt, go back and read Tufte. (W.W.T.D.?)
[...] gridlines, axis, legend, titles, labels etc.) and resize it so that it fits nicely in a cell [example]. This is the easiest and cleanest way to get sparklines in earlier versions of excel. However this [...]
thanks for the work creating the template!!!!
looks good