CDO

I have files with four 6-hr analyses per day for a month, so ~120 records per month, for all the Januaries (10) in the period of record. Therefore each month file consists of ~1200 records. I would like to calculate monthly statistics (mean, min, max, std) for January, February, .... I cannot figure out from the documentations if there is a math/stats function that iterates over a file so constructed and calculates these parameters, Since this is not strictly a time series, I'm unsure if this is possible from one of the statistical operators which all seem to prefer time series. Timmean and friends seem to do what I want, but the documentation and metadata confuse the issue for me. Are those the right functions to use in this case?