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AH = 00hReturn:
CX:DX = number of clock ticks since midnightAL = midnight flag, nonzero if midnight passed since time last read
Notes:There are approximately 18.2 clock ticks per second, 1800B0h per 24 hrs(except on Tandy 2000, where the clock runs at 20 ticks per second).IBM and many clone BIOSes set the flag for AL rather than incrementingit, leading to loss of a day if two consecutive midnights passwithout a request for the time (e.g. if the system is on but idle).Since the midnight flag is cleared, if an application calls thisfunction after midnight before DOS does, DOS will not receive themidnight flag and will fail to advance the date.Modern releases of MS-DOS/PC DOS (5.0+???) assume that AL is a dayrollover counter rather than a flag, as expected by older releases.DOS 5 - 7.10 (Windows 98 SE) provide an undocumented CONFIG.SYSSWITCHES=/T option to force the old behaviour of the day advancingcode, that is using a flag instead of a counter..DR DOS 3.31 - DR-DOS 7.03 handle AL as a flag.
See Also:AH=01h -AH=02h -INT 21/AH=2Ch -INT 55"Tandy See Also:INT 62/AX=0099h - MEM 0040h:006Ch - MEM 0040h:0070h
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