Essentially identical calendars rejected by IRIS
This is an issue that was brought up by Lars Bärring in bias adjusting "RCA4/EC-EARTH/r12/rcp2.6." which has a calendar "gregorian", while the reference data set has "proleptic_gregorian". The calendars are identical for the given time period (only differ in the 16th century) and should idealy be accepted by IRIS. Also the calendar "standard" should be accepted (if not already).
We need a solution to handle this issue online in the code rather than offline by pre-processing of files. Contact Lars Bärring for a complete setup description.
This is high priority since it is needed for the scenarioservice production. First, investigate how large an effort it is to solve in the code. If "too large", we propose a pre-processing.