use more straitforward code because otherwise error occurs with non-s…

…tandard calendar

pcmdi_metrics/mjo/lib/mjo_metric_calc.py

@@ -54,8 +54,18 @@ def mjo_metric_ewr_calculation(
  print("debug: check time")
 
  time_key = get_time_key(ds)
- first_time = ds.indexes[time_key].to_datetimeindex()[0].to_pydatetime()
- last_time = ds.indexes[time_key].to_datetimeindex()[-1].to_pydatetime()
+
+ # Get first time step date
+ first_time_year = ds[time_key][0].item().year
+ first_time_month = ds[time_key][0].item().month
+ first_time_day = ds[time_key][0].item().day
+ first_time = datetime(first_time_year, first_time_month, first_time_day)
+
+ # Get last time step date
+ last_time_year = ds[time_key][-1].item().year
+ last_time_month = ds[time_key][-1].item().month
+ last_time_day = ds[time_key][-1].item().day
+ last_time = datetime(last_time_year, last_time_month, last_time_day)
 
  if season == "NDJFMA":
  # Adjust years to consider only when continuous NDJFMA is available