FileMaker Pro Custom Functions

Can you find it.I hop you cn find it in a good.

william royster, ohio
March 26, 2009 7:45am

Just one little addition to the leap year factor that might be easily forgotten...
The year 2000 is not a leap year, because it's divisible by 400.

Let ( leapFactor = If ( Mod ( Year ( theDate ) ; 4 ) = 0 AND Mod ( Year ( theDate ) ; 400 ) ≠ 0 ; 1 ; 0 );

Alexis Gehrt, Laax / Switzerland
November 30, 2009 8:35am

Sorry, Alexis, but check your calendar again. 2000 WAS a leap year, because it's divisible by 400. The 'century' years are normally not leap years (1800, 1900), except when divisible by 400. So the calc for leapFactor should really be:

leapFactor = Case ( Mod ( Year ( theDate ) ; 400 ) = 0 ; 1 ;
// 'century' years divisible by 400 are leap years
Mod ( Year ( theDate ) ; 100 ) = 0 ; 0 ;
// 'century' years not divisible by 400 are not leap years
Mod ( Year ( theDate ) ; 4 ) = 0 ; 1 ;
// years divisible by 4 are leap years
0 )

Rob Woof, Sydney/Australia
August 08, 2010 7:13pm

There's another way that bypasses the Case statement.

leapFactor = If ( Mod ( Year ( theDate ) ; 400 ) = 0 ; 1 ; 0 ) // 'century' years divisible by 400 are leap years
- If ( Mod ( Year ( theDate ) ; 100 ) = 0 ; 1 ; 0 ) // 'century' years not divisible by 400 are not leap years
+ If ( Mod ( Year ( theDate ) ; 4 ) = 0 ; 1 ; 0 ) // years divisible by 4 are leap years

A year that is divisible by 400 (e.g. 1600, 2000) will evaluate to 1 - 1 + 1 = 1.
A year that is divisible by 100 but not by 400 (e.g. 1300, 1900) will evaluate to 1 - 1 + 0 = 0.
A year that is divisible by 4 but not by 100 (e.g. 1972, 1988) will evaluate to 1 - 0 + 0 = 1.
Any other year (i.e. not a leap year) will evaluate to 0 - 0 + 0 = 0.

Just another way to skin this particular cat.

Rob Woof, Sydney/Australia
August 11, 2010 8:48pm

No need to do this at all: FileMaker will handle leap years itself if you use it's own date comparisons.
Go look at http://www.briandunning.com/cf/518

That one lets you pick a comparison date (just use Get( CurrentDate ) for the second parameter if you want current age), handles negative age comparisons, and returns multiple formats.

Also, it has the decided advantage of actually returning correct values, even when dealing with leap years and on the actual birthday anniversary because it uses FileMaker's own date comparisons to get it right.

Daniel A. Shockley, New York, NY
May 04, 2011 11:16am