Rule to find cells in column A that correspond to multiple values in column B

[margaretanne]

I have an Excel sheet with several columns. Column A is an ID number for a person. Column B is the date when the person joined an organization. Some people join the organization more than once, and thus have several dates. These are the people (rows) I need to highlight with a conditional formatting rule.

Additional information in column C means that some people that only have one date still split accross multiple rows (and that's how I want it), so simply searching for duplicates will not work.

Example:

Col A - Col B

Karen - 01/11/12
Karen - 01/11/12
Patsy - 02/01/11
Patsy - 04/01/99
Ciara - 09/18/04

In the above example, Karen and Ciara are both fine, but I want a rule to highlight Patsy's name (ID number in column A) since she has two different dates.

To take it a step further, it would be even more helpful to--instead of highlighting Patsy's name--to highlight the entire row containing the most recent date:

Patsy - 02/01/11

Please and thank you!

[margaretanne]

Nevermind! I think I figured out a work around. I entered this formula into the last column:

=if(and(a2=a3, b2<>b3), "Fix", "Fine")

after sorting the columns by ID number and then date. Then I can just add conditional formatting based on that last column to highlight the "fix" rows.

Thanks anyway!