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.
13 Responses to “Data Validation using an Unsorted column with Duplicate Entries as a Source List”
Pivot Table will involve manual intervention; hence I prefer to use the 'countif remove duplicate trick' along with 'text sorting formula trick; then using the offset with len to name the final range for validation.
if using the pivot table, set the sort to Ascending, so the list in the validation cell comes back alphabetically.
Hui: Brillant neat idea.
Vipul: I am intrigued by what you are saying. Please is it possible to show us how it can be done, because as u said Hui's method requires user intervention.
Thks to PHD and all
K
Table names dont work directly inside Data validation.
You will have to define a name and point it to the table name and then use the name inside validation
Eg MyClient : Refers to :=Table1[Client]
And then in the list validation say = MyClient
Kieranz,
Pls download the sample here http://cid-e98339d969073094.skydrive.live.com/self.aspx/.Public/data-validation-unsorted-list-example.xls
Off course there are many other ways of doing the same and integrating the formulae in multiple columns into one.
Pls refer to column FGHI in that file. Cell G4 is where my validation is.
Vipul:
Many thks, will study it latter.
Rgds
K
[...] to chandoo for the idea of getting unique list using Pivot tables. What we do is that create a pivot table [...]
@Vipul:
Thanks, that was awesome! 🙂
@Playercharlie Happy to hear that 🙂
Great contribution, Hui. Solved a problem of many years!
Thanks to you, A LOT
Hi Hui,
Greeting
hope you are doing well.
I'm interested to send you a private vba excel file which i need to show detail of pivot in new workbook instead of showing in same workbook as new sheet.
Please contact me on muhammed.ye@gmail.com
Best Regards