Calculate absence in a period

Hi,
Can you tell me how i would calculate the number of sickness days and occaisions in the previous 26 week period from todays date.

I've attached the spreadsheet.

So in C4 i want to have the total number of times(occasions) the person has been absent in the previous 26 weeks.

and in E4 i want to have the Total number of Days (taken from E7:E20) the person has been sick in the past 26 weeks