code: def assert_daily(var):
      r
  
      t0, t1 = var.time[:2]
  
      # This won't work for non-standard calendars. Needs to be implemented in xarray. Comment for now
      if isinstance(t0.values, np.datetime64):
          if pd.infer_freq(var.time.to_pandas()) != 'D':
              raise ValueError("time series is not recognized as daily.")
  
      # Check that the first time step is one day.
      if np.timedelta64(dt.timedelta(days=1)) != (t1 - t0).data:
          raise ValueError("time series is not daily.")
  
      # Check that the series has the same time step throughout
      if not var.time.to_pandas().is_monotonic_increasing:
          raise ValueError("time index is not monotonically increasing.")
docs: r"""Assert that the series is daily and monotonic (no jumps in time index).
  
      A ValueError is raised otherwise.