code: def to_cds_time(time):
      """Convert datetime to (days, msecs) since 1958-01-01."""
      if isinstance(time, datetime):
          time = np.datetime64(time)
      t0 = np.datetime64("1958-01-01 00:00")
      delta = time - t0
      days = (delta / np.timedelta64(1, "D")).astype(int)
      msecs = delta / np.timedelta64(1, "ms") - days * 24 * 3600 * 1e3
      return days, msecs
  
imports: from datetime import datetime
  from unittest import mock
  import numpy
  import pytest
  import xarray
  from satpy.readers.seviri_l1b_nc import NCSEVIRIFileHandler
  from satpy.tests.reader_tests.test_seviri_base import ORBIT_POLYNOMIALS
  from satpy.tests.reader_tests.test_seviri_l1b_calibration import TestFileHandlerCalibrationBase
  from satpy.tests.utils import assert_attrs_equal, make_dataid
label_desc: Use image node_id 1 for calling a global function with example usage: to_cds_time(time) and returns: days,  msecs