Identifying Overlapping Dates Per Product

[cheesiepoof05]

Hello, I'm trying to find a formula that will help me to identify any dates that are overlapping by each Animal in column C. I have an example below where two lines of the cat and two lines of the mouse overlap so I would like an error message pointing out those four rows. Thanks!

[TABLE="width: 500"]
<tbody>[TR]
[TD="align: center"]C[/TD]
[TD="align: center"]K[/TD]
[TD="align: center"]L[/TD]
[/TR]
[TR]
[TD]Animals[/TD]
[TD]Start Date[/TD]
[TD]End Date[/TD]
[/TR]
[TR]
[TD]Dog[/TD]
[TD]7/1/2012[/TD]
[TD]6/30/2013[/TD]
[/TR]
[TR]
[TD]Dog[/TD]
[TD]7/1/2013[/TD]
[TD]6/30/2014[/TD]
[/TR]
[TR]
[TD]Dog[/TD]
[TD]7/1/2014[/TD]
[TD]6/30/2015[/TD]
[/TR]
[TR]
[TD]Cat[/TD]
[TD]7/1/2012[/TD]
[TD]6/30/2013[/TD]
[/TR]
[TR]
[TD]Cat[/TD]
[TD]3/15/2013[/TD]
[TD]6/30/2014[/TD]
[/TR]
[TR]
[TD]Cat[/TD]
[TD]7/1/2014[/TD]
[TD]6/30/2015[/TD]
[/TR]
[TR]
[TD]Cat[/TD]
[TD]7/1/2015[/TD]
[TD]6/30/2016[/TD]
[/TR]
[TR]
[TD]Mouse
[/TD]
[TD]7/1/2012[/TD]
[TD]6/30/2013[/TD]
[/TR]
[TR]
[TD]Mouse[/TD]
[TD]7/1/2013[/TD]
[TD]6/30/2014[/TD]
[/TR]
[TR]
[TD]Mouse[/TD]
[TD]7/1/2014[/TD]
[TD]3/30/2016[/TD]
[/TR]
[TR]
[TD]Mouse[/TD]
[TD]7/1/2015[/TD]
[TD]6/30/2016[/TD]
[/TR]
</tbody>[/TABLE]

 

[steve the fish]

Try this:

=IF(COUNTIFS($C$2:$C$12,C2,$L$2:$L$12,">="&K2,$K$2:$K$12,"<="&L2)>1,"ERROR","OK")

 

[cheesiepoof05]

Perfect, thank you so much for your help!

Try this:

=IF(COUNTIFS($C$2:$C$12,C2,$L$2:$L$12,">="&K2,$K$2:$K$12,"<="&L2)>1,"ERROR","OK")