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 FileMaker Pro Custom Functions

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MonthNumber ( monthName )

Rate this function:  

  Average rating: 4.4  (43 votes)
  Discuss this Custom Function

David Head, uLearnIT

Convert month name to a number

Sample Input:
MonthNumber ( "September" )
Sample Output:

 Then copy & paste into FileMaker Advanced's Edit Custom Function window.


Returns the month number for any month name.

Note: these functions are not guaranteed or supported by Please contact the individual developer with any questions or problems.

This is my Custom Function and I want to edit it


The function parameter name cannot be "monthName" because FileMaker 11 has a MonthName function. I changed the name to "text".

Ward Clark, Townsend, MA
May 15, 2010 10:54am

Very clever. Great use of custom functions.

Thomas Keller, Portland
September 03, 2010 11:34am

I wanted to be able to get the month number out of a complete date no matter where it was located (e.g. "January 1, 2012" or "08-FEB-12"), so I filtered:

"xxJanFebMarAprMayJunJulAugSepOctNovDec" ;
Left ( Filter (text; "JjAaNnFfEeBbMmYyUuLlGgSsPpOoCcTtVvDd" ); 3 ) ;
1 ;

Eric Matthews, San Jose, CA
February 17, 2012 2:58pm

Hi Eric
Good feedback.

The CF was designed to accept either a month name or an expression that results in a month name e.g. Monthname ( dateField ). So you have modified it to accept any input that may contain a month name. Fair enough use.

This is a clever way to filter the required treat out of the string and then pass it to the function. Obviously the 'complete date' you are parsing is text not date. You have correctly used upper and lower case because the Filter function is case-sensitive. However, you have omitted "r" :)

So I would tend to be more comprehensive and filter every possible letter to ensure completeness. I would also convert to uppercase (or lower) first to avoid the need for duplication:


Anyway, a good addition to the functionality of the CF. :)
Cheers, David

David, Sydney, Australia
February 17, 2012 5:05pm

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