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 FileMaker Pro Custom Functions

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CalcDaysBetween ( startDate ; endDate ; numDays ; $$HolidayList ; countWeekends ; returnNeg )

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  Average rating: 3.9  (62 votes)
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Shan Younker, Shan Younker

Calculates number of days between dates, accounts for holidays and weekends

Sample Input:
CalcDaysBetween ( 7/1/2009 , 7/9/2009, 0, $$Holidays, False, "" )
Sample Output:

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


Calculates the number of days between two dates. Will not count holidays or weekends if passed a variable with a list of holidays.

When you initially call the function, pass a start and end date. Use 0 for numDays - this gets incremented each time through the loop. Pass a pre-populated list of holidays from a variable. CountWeekends - pass 'true' if you want to count weekends and holidays in numDays, pass 'false' if you don't. For returnNeg, pass "" when calling the function, if the startDate is after the endDate then the function will return a negative number for numDays.

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


5 most recent comments | Show all 7 comments

Thank you for developing this custom function - I have found it to be very useful ...

But I need to report a bug!

When working with negative results, the 'ReturnNeg' variable is not consistently 'True'. I have tracked this down to a missing entry (shown in caps and quotes) in the formula - see below;

//first time through function determine if negative numDays should be returned.
returnNeg =
Case (
IsEmpty ( returnNeg );
Case (
endDate > startDate ; False;
startDate > endDate;
True ) "RETURNNEG" );

Perhaps once you have checked this, you could report back here if you concur.

Thanks again - Alan

Alan Stirling, London UK
July 13, 2009 3:09pm

I like this custom function. I found some bugs for end case scenarios. I modified it with corrections, and removed the negative numDays option for myself. Please contact me, Shan, if you would like to see my work.


Jonn Howell, Los Angeles, CA
August 08, 2010 3:31pm

Hi Jonn,

Are you able to share the corrections/modifications here?

Michael, Brisbane Australia
August 11, 2010 4:13pm

Hi Jonn,

I'm battling to get this one to work, would you share your corrections?

Sean Newton, Durban RSA
March 18, 2011 1:04am

Hi Shan,

I am using your other cf - calcEndDate - Thank you, it is very useful. This one does not work though.

Sean Newton, Durban RSA
March 23, 2011 4:48am

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