AH = 05h: Set RTC Date

This function sets the date in the real-time clock. Also, this function sets bit 7 of the BIOS RAM variable [SysFlags].

• Input: AH = 05h
  CH = Century in BCD:
  19h if 20th century
  20h if 21st century
  CL = Year in BCD
  DH = Month in BCD
  DL = Day in BCD
  Carry Clear

• Output: AH = 00h
• Error conditions: Carry Set if RTC inputs invalid, or old RTC data invalid.
• Registers modified: AX, STATUS