Suppose you have a data time series that is taken every day. Say, like Arctic sea ice extent from NSIDC.
Let's say you want to calculate it's moving annual average -- over 1-yr, 12-mths, 365.25 days.
How, exactly, do you account for leap year days in such a moving average?
PS: I was born on a leap year day, February 29th -- the only baby in the hospital to have been delivered on that day -- but don't worry about upsetting me no matter whatever you propose. I've heard all the jokes, and I like being only a decade and a half old, more or less. It makes me feel just a bit special.
PPS: I also defended my PhD thesis on a Feb 29th. After my hour-long 4:00 pm presentation they voted me up just one hour before the hour I was born, so I can say I got my Phd when I was 27.