docs: def cmd():
      """Implementation of time subcommand.
  
      Other Parameters:
          conf.time
          conf.core
      """
      sdat = StagyyData(conf.core.path)
      if sdat.tseries is None:
          return
  
      if conf.time.fraction is not None:
          if not 0 < conf.time.fraction <= 1:
              raise InvalidTimeFractionError(conf.time.fraction)
          conf.time.tend = None
          t_0 = sdat.tseries.iloc[0].loc['t']
          t_f = sdat.tseries.iloc[-1].loc['t']
          conf.time.tstart = (t_0 * conf.time.fraction +
                              t_f * (1 - conf.time.fraction))
  
      lovs = misc.list_of_vars(conf.time.plot)
      if lovs:
          plot_time_series(sdat, lovs)
  
      if conf.time.compstat:
          compstat(sdat, conf.time.tstart, conf.time.tend)