Formula for finding duplicates ehtry on different dates

Hi Friends,

I need help in creating a formula that will identify duplicate entries of invoice #'s but only for different dates. I am using the formula " =IF(COUNTIF($U$2:U2,U2)>1,"Duplicate","") " which does identifies the duplicates but it is identifying the duplicate entries done on the same date as well. Which I do not want to be highlighted.

Can anyone help me on the same urgently.

Thanks,
Amit

Can you upload a sanitized sample file that demonstrates the problem you're having and your desired outcome?

Attached is the sample, basically I have a lot of data in multiple columns and what I am trying to do is to find the duplicate invoice number if entered on a different date, but in case the invoice number is a repeat on a same day it should not be highlighted as a duplicate.

I added Column I to check for duplicates. But first I sorted by PO. Cells with equations are highlighted in green. Does this work?

Is there a way to do this without sorting the data, as this sheet is a running sheet with 100-150 entries updated in this sheet on a daily basis. So, sorting the data by invoice numbers on a daily basis will be an additional step and in case someone misses out on performing this step the report generated will not show true numbers.