Any updates needed due to CF version 1.9 is deprecating gregorian calendar?

[larsbarring]

Are there any implications for cftime because of CF version 1.9 is deprecating gregorian calendar as synonym for the standardmixed Julian/Gregorian calendar? One possible example that I recently came across is name of the datatype DatetimeGregorian; maybe it should be DatetimeStandard instead?

[jswhit]

PR #257 causes a DeprecationWarning to be raised if calendar='gregorian' is used. A DatetimeStandard class was added, but DatetimeGregorian is kept for backwards compatibility.

[davidhassell]

Hello, Is it right to raise a warning if calendar='gregorian' is used? For the nearly all existing CF-netCDF datasets at time of writing (i.e. those at CF<=1.8), gregorian is valid and so using cftime to parse such a file would, I feel, lead to an inappropriate message. I think silently changing the calendar to standard in such cases is fine, as this PR would do without these warnings. What do you think?

This warning pops up in two places:

cftime/src/cftime/_cftime.pyx

Lines 1053 to 1054 in 67eeb68

	if calendar == 'gregorian':
	msg="calendar name 'gregorian' deprecated in CF v1.9 (use 'standard' instead)"

cftime/src/cftime/_cftime.pyx

Lines 1770 to 1771 in 67eeb68

	if calendar == 'gregorian':
	msg="calendar name 'gregorian' deprecated in CF v1.9 (use 'standard' instead)"

Thanks, David

[larsbarring]

I raised this issue as a question, and think that it might be reasonable to automagically change fromgregorian calendar to standard as they were synonyms. But I am not the right person to comment whether it should be done silently or not.

[jswhit]

I went ahead and removed the DeprecationWarning, and now gregorian is just silently changed to standard. I think @davidhassell is right, since 'gregorian' has been in use since forever, that warning would be annoying.