Rollin gYear Formula

You guys were great at helping me out last year and I am hoping your expertise can help again.


I have a spreadsheet for calulating the number of sick days in a rolling year, which is calculated from the last day of sickness. The formula is below - C12 is always the last date of sickness.

=IF(ISBLANK(C12),0,SUMIF($C$17:$C66,">="&$C12-365,$D$17:$D66))

Within this formula I also need it to return a value of 0 if the last sick day was more than a year previous...any ideas on what I should do?


Similiarly, the following formula, calculates the number of times someone has been off sick in a rolling year, again it looks at the last date of sickness, if this was than 12 months previous how can I get a results of 0?

=COUNTIF(C17:C76,">"&C12-365)
and
=IF(ISBLANK(C17),0,COUNTIF(C17:C17,">"&C17-365))

Any help would be greatly appreciated