def _update_time(self):
self.time['<STR_LIT>'] += <NUM_LIT:1><EOL>self.time['<STR_LIT>'] += self.time['<STR_LIT>'] / const.seconds_per_day<EOL>if self.time['<STR_LIT>'] >= self.time['<STR_LIT>']-<NUM_LIT:1>:<EOL><INDENT>self._do_new_calendar_year()<EOL><DEDENT>else:<EOL><INDENT>self.time['<STR_LIT>'] += <NUM_LIT:1><EOL><DEDENT>
Increments the timestep counter by one.

        Furthermore ``self.time['days_elapsed']`` and
        ``self.time['num_steps_per_year']`` are updated.

        The function is called by the time stepping methods.