DateAdd Function

[Michael Meeks]

Hi all,

Stump'd as usual...

Here's my problem:

In VB - The DateAdd Function makes it easy!

dwAddDate = 1044890128
dwBiasTimeSecs = 32400
strStartDate$ = "1/1/1970"

DateOfEvent$ = DateAdd("s", CLng(dwAddDate) - dwBiasTimeSecs, strStartDate$)

DateOfEvent$ results will equal: "2/10/2003 6:15:28 AM"

How do I do the equivalent in PowerBasic?


Regards
Mike

[Peter Redei]

see http://www.powerbasic.com/support/pb...ad.php?t=23736

------------------

[Michael Meeks]

Peter,

Too many problems with the source code! (at least with PB7)
GPF's all over the place!

Regards
Mike

[Don Schullian]

I think everything you need is here. Shout if not.

'%DateOffset = 584388                ' Subtraction of this value to the date
                                     ' numbers will render returns the same
                                     ' values as Windows' FileTime date number
                                     ' NOTE: Sunday = ((Days MOD 7) = 1)
                                     ' NOTE: Dates before 1601-01-01 are invalid
                                     '       for Windows
'%DateOffset = 685195                ' Jan. 1, 1877 was a Monday and Subtraction
                                     ' of this number will render the return in
                                     ' WORD format. Last Date would be 2056-12-31
%DateOffset = 0                      '

FUNCTION fLeapYear ALIAS "fLeapYear" (BYVAL Year AS LONG) EXPORT AS LONG

  IF ( ( Year MOD   4 ) = 0 ) AND _
     ( ( Year MOD 100 ) > 0 )  OR _
     ( ( Year MOD 400 ) = 0 ) THEN FUNCTION = 1

END FUNCTION
'
'
'
FUNCTION fJulianDay ALIAS "fJulianDay" (BYVAL Year  AS LONG, _
                                        BYVAL Month AS LONG, _
                                        BYVAL Day   AS LONG  ) EXPORT AS LONG

  Day = Day + VAL(READ$(Month))
  IF Month > 2 THEN
    Day = Day + fLeapYear(Year)
  END IF

  FUNCTION = Day

  DATA 000, 031, 059, 090, 120, 151
  DATA 182, 212, 243, 273, 304, 334

  FUNCTION = Day                                         'RETURN Day number for the year

END FUNCTION            
'
'
'
FUNCTION fDays2YMD ALIAS "fDays2YMD" (BYVAL Days  AS LONG, _
                                            Year  AS LONG, _
                                            Month AS LONG, _
                                            Day   AS LONG  ) EXPORT AS LONG

  DIM DoW  AS LOCAL LONG
  DIM Temp AS LOCAL LONG

  DoW  = (Days MOD 7)
  Days = Days + %DateOffset
  Year = (Days \ 365)
  Temp = (Year \ 4) - (Year \ 100) + (Year \ 400)
  Days = (Days MOD 365) - Temp

  WHILE Days < 1
    Days = Days + 365 + fLeapYear(Year)
    DECR Year
  WEND

  INCR Year

  Julian2MD Year, Days, Month, Day

  FUNCTION = DoW

END FUNCTION           
'
'
'
FUNCTION fYMD2Days ALIAS "fYMD2Days" (BYVAL Year  AS LONG, _
                                      BYVAL Month AS LONG, _
                                      BYVAL Day   AS LONG  ) EXPORT AS LONG

  DIM DoM AS LOCAL LONG

  IF ( Year  = 0 )   OR _
     ( Month = 0 )   OR _
     ( Day   = 0 ) THEN EXIT FUNCTION

  IF Month > 1 THEN Day = fJulianDay(Year,Month,Day)     'compute Julian day
  DECR Year                                              'don't count 'this year'
  Day = Day + (Year * 365) + _                           ' add full years
              (Year \   4) - _                           ' add a day for each olympiad
              (Year \ 100) + _                           ' subtract a day for each century
              (Year \ 400)                               ' add a day for each epoc
                                                         '
  FUNCTION = Day                                         'RETURN day count
                                                         '  unREM to use WORDs
END FUNCTION

------------------
C'ya
d83

[David L Morris]

Michael,

Do you realize Peter's posting contains three files - one to be compiled
as a DLL, one as a header.inc and the third a simple exe? I used PB7 and it
seemed to run all fine.

David

------------------

[Michael Meeks]

David,

Try using the data - I posted above in my first post and you
should see what I mean...

v1 = 1044890128 
v2 = 32400      


Results$ = DateAdd("s", v1-v2, "1/1/1970")

The above code GPF'd - however, when walking it through using
the debugger - It started to spit out heap errors in the debugger
window!

Currently - going through it line by line (slow process) - to
produce the same results - only without crashing!

addition to notes: Yes, 3 files - which I incorparted into 1.
And so, I could walk the pb-debugger through completely - even
with the errors - and get correct results! But I can't run the
program without GPF'n!

Regards
Mike


[This message has been edited by Michael Meeks (edited February 11, 2003).]

[Tom Hanlin]

I see that DateAdd expects to receive an ASCIIZ value, but then goes
on to pass this directly to functions that expect STRING values. This
is not likely to be a happy combination, and may be the cause of the
problem.

------------------
Tom Hanlin
PowerBASIC Staff

[David L Morris]

Yes Michael I do get some errors and also some wrong results.

There is another module I have used, apart from the API procedures. The source
can be found in a posting in 1999 by Brent Thompson:-
http://www.powerbasic.com/support/fo...-7-000189.html

or do a search on DATESERIAL with author Brent Thompson

I hope is might help

David

------------------

[Michael Meeks]

Thanks, Tom, David,

David, That link look promising!

Regards
Mike