Ranking Duplicate values

[StephenVWard]

Please help. Thank you in advance. I am looking to rank only duplicates in a list on a different column criteria based on date. If their are no duplicates it would stay at 1. If duplicates, it would rank based on date in a decending or ascending order. For example.

Column A has values:
237
176
876
237
176
237
237

Column B has a date
2/1/13
2/1/13
2/1/13
5/6/13
5/12/13
8/10/13
9/8/13

Looking to get the following on Column C
1
1
1
2
2
3
4

 

[joemeshuggah]

if your dates in column b are always in chronological order, this would work =COUNTIF(A$1:A1,A1)