Create A summary based on Existing Data

Hi,

I need your help with a workbook. A sheet has different customer names I've done the conditional formatting so that it is highlighted in that particular sheet.

My requirement: I have a blank summary sheet which i need populated based on month. Say this is April, i want to be able to see the April names and the next month I need to be able to see the May name.

All help is much appreciated !

God Bless