# File lib/ri_cal/fast_date_time.rb, line 136
    def adjust_day_delta(day_delta, new_secs_since_bod)
      if new_secs_since_bod == 0
        [day_delta, new_secs_since_bod]
      elsif new_secs_since_bod > 0
        [day_delta + (new_secs_since_bod / SECONDS_IN_A_DAY), new_secs_since_bod % SECONDS_IN_A_DAY]
      else
        [day_delta - (1 + new_secs_since_bod.abs / SECONDS_IN_A_DAY), 
         SECONDS_IN_A_DAY - (new_secs_since_bod.abs % SECONDS_IN_A_DAY)]
      end
     end