Hi again,

Am Mon, 11 May 2015 18:28:36 +0200 schrieb Claus Busch:

in D2 try:
=IF(MATCH(B2&C2,B$1:B$100&C$1:C$100,0)=ROW(),"N"," Y")

if you have Excel versio n 2007 or later you can also try in D2:
=IF(COUNTIFS($B$2:B2,B2,$C$2:C2,C2)=1,"N","Y")

sorry, but you wanted the column with teh timestamp as criteria also:
Then try in D2:
=IF(MATCH(A2&B2&C2,A$1:A$100&B$1:B$100&C$1:C$100,0 )=ROW(),"N","Y")
and enter with CTRL+Shift+Enter.
The first occurance is not signed as duplicate! Only the following
entries.

Or:
=IF(COUNTIFS($A$2:A2,A2,$B$2:B2,B2,$C$2:C2,C2)=1," N","Y")
This formula writes a Y to all duplicates


Regards
Claus B.
--
Vista Ultimate / Windows7
Office 2007 Ultimate / 2010 Professional