Need HELP! need to create a 6 month rolling calendar or reversal ( New to Excel)

Okay so I need to create an attendance sheet that basically stays current. I don't want to manually add up point within a 6 month time frame. So I need any points accumulated after 6 months to not go within the total points. So for example today is July 11th. So anything older than 1/9/2014 should automatically not be counted. I did today's date - 183 to get to 1/9/2014 seeing as there are 365 days in a year. I'm open to any suggestion, need to create a low maintenance attendance sheet for my boss ASAP. Just having a problem on how to actually make it low maintenance!


I can email what I have so far, can't get to upload on here.