code: def simindices(self):
          
          return (hydpy.pub.timegrids.init[hydpy.pub.timegrids.sim.firstdate],
                  hydpy.pub.timegrids.init[hydpy.pub.timegrids.sim.lastdate])
docs: Tuple containing the start and end index of the simulation period
          regarding the initialization period defined by the |Timegrids| object
          stored in module |pub|.