Brian Dunning's FileMaker Custom Functions

SubtractTimes ( Time1 ; Time2 )

Subtract one time from another; both times in h:mm:ss format

  Average rating: 4.8 (23 votes) Log in to vote

Bill Thurmes   Bill Thurmes - Show more from this author

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  Sample input:
SubtractTimes ( "59:43" ; "28:13" )
SubtractTimes ( "2:01:58" ; "29:54" )
  Sample output:

  Function definition: (Copy & paste into FileMaker's Edit Custom Function window)

Time2 will be subtracted from Time1
Entry format should be h:mm:ss, or mm:ss, or ss.
Result will be in same format, dropping unneeded info from left.
Primarily useful if data is/might be in a mm:ss format
It now gives the correct answer if Time1 is earlier than Time2
Changed 4/12/19 to work better



comment   comment, VR
Apr 10, 2014
Filemaker can add and subtract times natively.
Bill Thurmes   Bill Thurmes, MDCA
Apr 11, 2014
Thanks, VR. I had needed something to subtract text that was in a mm:ss format, which Filemaker's native time addition doesn't deal with well. I've changed the script to use Filemaker's native capabilities.
K.C.   K.C., San Francisco
Oct 17, 2014
Is there a way to accept non military time? If time 1 occurs before noon, and time 2 occurs after noon, the results are in the wrong direction.
Bill Thurmes   Bill Thurmes, MDCA
Oct 22, 2014
I assume you want a negative result when Time1 is before Time2? That it didn't work before was a bug in my function; in the final case statement I had forgotten to apply sign to t; I've fixed that now.

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