Xios gregorian calendar actually is proleptic gregorian

[ssenesi]

See explanations at ​https://github.com/PCMDI/cmor/issues/325

[ymipsl]

So what do you suggest ?

[ssenesi]

At least to fix the doc, and the value of calendar_type written in datafiles, in order that datafiles are consistent

[ssenesi]

You could also adopt the follwoing rule:

1- if user requests a gregorian calendar

• if he does not set a reference time before 15 october 1582, OK (don't change anything in code)
• otherwise, just exit (at least as long as Xios cannot really handle a gregorian calendar for early dates in the Julian era)

2- if the user requests a proleptic_gregorian calendar : OK, just do not change anything in Xios logic (except for he calendar_type value in datafiles)

[ssenesi]

This is not an urgent matter, anyway.