 BCD to Julian Date                   - BCD2JUL
 Binary to Julian Date                - BIN2JUL
 Julian Date to Binary                - JUL2BIN
 Binary Number to BCD                 - BINBCD
 BCD to Binary Digit                  - JBCD2BN
 BCD date to Day of Week              - WDAY0
 Test BCD Date and Time for Validity  - ISBCDD, ISBCDT
 Test Byte for BCD                    - ISBCD
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BCD2JUL - BCD date to Julian date conversion.

  ENTER: HL = address of date as BCD yy mm dd.
  EXIT:  HL = Julian date in binary (1/1/1978 = 1).
  USES:  HL

Usage: If the year is less than 1978, this routine wraps to the next 
century, covering dates from 1/1/1978 through 12/31/2077.
:
BIN2JUL - Binary date to Julian date conversion.

  ENTER: HL = address of date as binary yy mm dd.
  EXIT:  HL = Julian date in binary (1/1/78 = 1).
  USES:  HL

Usage: If the year is less than 1978, this routine wraps to the next 
century, covering dates from 1/1/1978 through 12/31/2077.
:
JUL2BIN - Julian date to binary date conversion.

  ENTER: HL = Days since 12/31/1977 (Julian date).
  EXIT:  B = Binary month (1=Jan ...),
         C = Binary year (78 ...),
         L = Binary day (1..31),
         A = L
  USES:  AF, BC, HL
:
BINBCD - Convert binary number to BCD.

  ENTER: A = binary number.
  EXIT:  A = BCD number.
  USES:  AF
:
JBCD2BN - BCD byte to binary digit.

  ENTER: A = number in BCD.
  EXIT:  A = binary number.
  USES:  AF, DE
:
WDAY0 - BCD date to day of week conversion.

  ENTER: HL = address of date as BCD yy mm dd.
  EXIT:  A = 0..6 representing day of week:
             0 = Saturday,
             1 = Sunday,
             2 = Monday,
             3 = Tuesday,
             4 = Wednesday,
             5 = Thursday,
             6 = Friday.
  USES:  AF
:
ISBCDD - Test BCD date and time for validity.

  ENTER: HL = address of possible BCD yy mm dd hh mm.
  EXIT:  Zero flag set (Z) if date and time ok:
           A = 2Ah ("*") if wildcard characters encountered,
           A = 0 if no wildcard characters encountered,
         Zero flag reset (NZ) and A = 0FFh if date and time invalid.
  USES:  AF

ISBCDT - Test BCD date and time for validity.

  ENTER: HL = address of possible BCD yy mm dd hh mm ss.
  EXIT:  Zero flag set (Z) and A = 0 if date and time ok,
         Zero flag reset (NZ) and A = 0FFh if date and time invalid.
  USES:  AF

Usage: ISBCDD checks only the first five BCD bytes of date string (not 
seconds).  ISBCDT checks all six bytes.  ISBCDT does not accept wildcard 
characters.
:
ISBCD - Test if byte is valid BCD.

  ENTER: A = byte to test
  EXIT:  Carry set (C) if byte is BCD,
         Carry reset (NC) if byte is invalid.
  USES:  AF
