0:470h                   Timer Overflow flag
 
 Length: 1 byte
 
    Keeps track of whether midnight has passed since the machine was
    powered on. See the 4-byte integer counter at 0:46Ch for more details.
 
  --------------------------------------------------------------------------
 
       Notes:         Note that this byte is only a flag. It either has a
                      value of 0 or 1. Therefore, it won't reflect a day
                      change over a two-day period.
 
                      Use INT 1Ah, Service 00h, to obtain this overflow
                      value. Note that doing so clears this byte.

Seealso:


 INT 1Ah, 00h 
 0:46Ch