Int 1A Fn 03  - Time - Set Real-time Clock Time (at,xt286,ps)              [B]

   AH = 03h
   CH = hour (BCD)
   CL = minutes (BCD)
   DH = seconds (BCD)
   DL = daylight savings flag (00h standard time, 01h daylight time)

See Also: AH=01h