code: def mjd2datetime64(mjd):
      """Convert Modified Julian Day (MJD) to datetime64."""
      epoch = np.datetime64("1858-11-17 00:00")
      day2nsec = 24 * 3600 * 1e9
      mjd_nsec = (
          (mjd * day2nsec).astype(np.int64).astype("timedelta64[ns]")
      )
  
      return epoch + mjd_nsec
  
imports: import logging
  from datetime import datetime
  import numpy
  import xarray
  from satpy.readers._geos_area import get_area_definition, get_area_extent
  from satpy.readers.hrit_base import HRITFileHandler, ancillary_text, annotation_header, base_hdr_map, image_data_function
  from satpy.readers.utils import get_geostationary_mask
label_desc: Use image node_id 1 for calling a global function with example usage: mjd2datetime64(mjd) and returns: unknown