Julian Date Function
Rick Roen
Here is a code snippet that I use to calculate the Julian date for encoding
into a shipping label.
This will set the JulianDate variable to the number of days since the
beginning of the year. I think there may be other formats that are used,
but you may be able to extrapolate how to get them from this code.
I setup the JulianDate as a string since I needed it in a "xxx" format. You
may need it as an integer, but that would be easy to change.
Rick
procedure GetJulianDate(var JulianDate: String);
var
year,month,day, DaysElapsed: word;
Jan1: TDateTime;
begin
JulianDate := '';
decodeDate(DM1.TShipWtDATE.AsDateTime,year,month,day);
Jan1 := EncodeDate(Year,1,1);
DaysElapsed := Trunc(DM1.TShipWtDATE.AsDateTime - Jan1) + 1;
JulianDate := format('%.3d',[DaysElapsed]);
end;
Simon Murrell wrote in message <36495619...@goaldata.co.za>...
>Hello
>
>Does anyone have a TDateTime converter to a Julian date format.
>
>Thanks
> Simon
>
James Lee Tabor
Here's a function converted from an NIST "C" language routine. It
returns the "modified Julian date". The C code is left in comments, any
error is translation is mine.
Jim
unit cvt2mjd;
//courtesy of -- time_a.timefreq.bldrdoc.gov
interface
function cvt2jd(yr, mo, day : LongInt) : LongInt;
implementation
//long int cvt2jd(yr,mo,day)
function cvt2jd(yr, mo, day : LongInt) : LongInt;
//int yr;
//int mo;
//int day;
//{
var
mjd, ilp : LongInt;
const
dom : array[1..12] of integer =
(0,31,59,90,120,151,181,212,243,273,304,334);
begin
//long int mjd; /*holds result*/
//int ilp; //number of leap years from 1900 not counting current
//static int dmo[12] = {0,31,59,90,120,151,181,212,243,273,304,334};
(*
this subroutine receives a date in the form year, month and day
and returns the MJD corresponding to that day. the year may
be specified as 90 or 1990.
*)
// if(yr > 1900) yr -= 1900; /* convert to years since 1900 */
if (yr > 1900) then
yr := yr - 1900;
// ilp=(yr-1)/4; /* number of leap years since 1900*/
ilp := (yr -1) div 4;
(*
compute number of days since 1900 + 1 day for each leap year
+ number of days since start of this year
*)
// mjd = 365*(long int) yr + (long int) (ilp + dmo[mo-1] + day - 1);
mjd := 365 * yr + (ilp + dom[mo-1] + day - 1);
// mjd += 15020; /* add MJD of 1900 */
mjd := mjd + 15020;
(*
if current month is jan or feb then it does not matter if
current year is a leap year
*)
// if(mo < 3) return(mjd);
if (mo < 3) then begin
Result := mjd;
exit;
end;
(*
if current month is march or later then must add 1 day if
current year is divisible by 4
*)
// if( (yr & 3) == 0) mjd++;
if ((yr and 3) = 0) then
inc(mjd);
Result := mjd;
// return(mjd);
//}
end;
end.
Simon Murrell
Mike Bandor
Simon,
In addition to the responses you have already received, on the
Delphi Super Page there is a JDATE component that gives Julian dates,
week numbers, etc. Best of all its FREE!
Mike
------------------------------------------------------
- Mike Bandor (ban...@vitrex.net)
- Software Engineer: Delphi/Ada/C++/Java/Win3.1/
- Win95/Winhelp/JOVIAL/MASM
-
- "Trying to manage programmers
- is like trying to herd cats!"
-
- Speaking for myself! Standard disclaimer applies.
------------------------------------------------------
- Author of MEGATERMS: Military Terms and Acronyms
- http://www.vitrex.net/~bandorm/megaterm/megaterm.htm
- ftp://vitrex.net/usr/b/bandorm/m-term.zip
------------------------------------------------------
Brandon Smith
Stockton's page at http://www.merlyn.demon.co.uk/index.htm for details on
some Pascal conversion routines and the code from my article from Issue 34
(june 98) of The Delphi Magazine at http://www.itecuk.com/delmag/index.htm.
Brandon C. Smith
B...@nospam.synature.com
http://www.synature.com
Dr John Stockton
15:05:13 in news:borland.public.delphi.objectpascal, James Lee Tabor
<ku...@wtrt.net> wrote:
>Here's a function converted from an NIST "C" language routine. It
>returns the "modified Julian date". The C code is left in comments, any
>error is translation is mine.
You might like to compare it with that in my (BP7) dateprox.pas, tested
with mjd_date.pas, compiled together into mjd_date.exe, all to be found
in URL: http://www.merlyn.demon.co.uk/programs/ - in mine, DMY_to_MJD is
general, and DMYtoMJD is Gregorian.
Conversion to Delphi looks easy enough (undefine FASTER).
--
John Stockton, Surrey, UK. j...@merlyn.demon.co.uk Turnpike v4.00 MIME.
Web <URL: http://www.merlyn.demon.co.uk/> - FAQqish topics, acronyms & links.
PAS, EXE in <URL: http://www.merlyn.demon.co.uk/programs/> - see 00index.txt.
Do not Mail News to me. Before a reply, quote with ">" or "> " (SoRFC1036)
astr...@my-dejanews.com
Might this have anything to do with the Platinum accounting product? If so, I
have a formula and can suggest a course of action. (please reply to
james....@mailexcite.com)
> Hello
>
> Does anyone have a TDateTime converter to a Julian date format.
>
> Thanks
> Simon
>
>
--
============================================
James Jensen
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