`xtime` variable in MPAS-Ocean conservationCheck analysis member incorrect

[Xylar Asay-Davis]

The value of the xtime variable in the first month of a simulation is incorrect in the conservationCheck analysis member from MPAS-Ocean. Whereas it is:

 xtime =
  "0001-02-01_00:00:00" ;

as expected for the second month (and so on for subsequent months), it is:

 xtime =
  "0000-01-15_00:00:00" ;

for the first month.

This, in turn, causes the MPAS-Analysis conservation analysis task to fail because this is an invalid date.

[Xylar Asay-Davis]

@cbegeman or @darincomeau, does either of you have any appetite to investigate and possibly fix this?