Hello, I have a really long list of names when people contacted my company, with their date of contact in the column next to it. I would like to be able to identify if the previous month was the first time someone contacted my company. So I need a formula (or macro) that would search the names column for duplicates and if the duplicate's date is outside of a specified range it will delete all instances. So I would be left with only the people that contacted us for the first time in that range. Thanks for your help in advance!