issue_comments: 130840069

Just so you see how messy this can be. The year 0000, because it does not exist, is used to store climatology in COARDS and CF. The coards package issued a warning but did the wrong thing:

python from coards import parse units = 'days since 0000-01-01 00:00:00' parse(0, units) coards/__init__.py:60: UserWarning: Shifted data 366 days to the future, since year zero does not exist. UserWarning) datetime.datetime(1, 1, 1, 0, 0)

If someone accidentally saves that date back with this object it will no longer be year 0 and other CDMs might choke by not recognizing it as climatology. cf_units does the right thing:

python import cf_units u = cf_units.Unit('days since 0000-01-01 00:00:00', calendar=cf_units.CALENDAR_NO_LEAP) ut = u.utime() ut.num2date(0) 0-01-01 00:00:00

But that object is pretty much useless for pandas and xray because of the non-standard calendar. The object is useful to annotate plots or to save the data metadata back the same way it was before.