docs: def parse_time_step(time_step, target='s', units_ref=None):
      """
          Read in the time step and convert it to seconds.
      """
      log.info("Parsing time step %s", time_step)
      # export numerical value from string using regex
      value = re.findall(r'\d+', time_step)[0]
      valuelen = len(value)
  
      try:
          value = float(value)
      except:
          HydraPluginError("Unable to extract number of time steps (%s) from time step %s" % (value, time_step))
  
      unit = time_step[valuelen:].strip()
  
      period = get_time_period(unit)
  
      log.info("Time period is %s", period)
  
      converted_time_step = units_ref.convert(value, period, target)
  
      log.info("Time period is %s %s", converted_time_step, period)
  
      return float(converted_time_step), value, period