[gradsusr] daily anomaly

[Sujata Mandke]

Dear Grads Users
    I wish to calculate daily OLR anomaly from
  the following datasets.
    I have daily OLR data (netcdf) for the period
   1Jun1974-31May2012. Also long term daily OLR
   climatology (netcdf) data for 365 days.

   As such writting script for calculating daily
  anomaly is very simple. But how to tackle following
    two problems while calculating anomaly

(i) Actual data is on Gregorian(real) calendar
    and thus has data for 366 days in leap years.
(ii) What to do with missing values?

Does anybody has grads script to calculate daily 
 anomaly by taking care of above two problems.
Regards
Dr. Sujata Mandke,Scientist,
IITM,PUNE-8,INDIA.