Subj : Julian to String Date
To   : All
From : Dan Egli
Date : Thu Jan 29 2004 12:02 am

Hey all. I need someone to double check my logic here, if you please. I am 
writing a function that takes a julian date (i.e. 030) and returns the String 
Date it represents(i.e. 01/30/<this year>). I wrote this function to do it. I 
am sure there is a more elegant way but I can not think of it. Basically I 
don't care as long as it works. So I want someone to double check it to see if 
they can see any flaws in my logic (entirely possible!).

This is for FreePascal so most Delphi 2.0 types are valid.

Thanks!
Dan
Moderator BBS_SURVIVAL


=== Begin Code ===
function JulToDateTime(JulDate : Word) : TDateTime;
var
  Y,M,D,Work : Word;
  IsLeap : Boolean;
  WorkDate : string;
begin
  Work := JulDate;
  DecodeDate(Date, Y, M, D);
  M := 1;
  D := 1;
  if (((Y mod 4) = 0) and (Y mod 100) >0)) or (Y mod 400) = 0) then
    IsLeap := true
  else
    IsLeap := false;
  if (Work > 31) then
  begin
    inc(M);
    Dec(Work, 31);
  end;
  if ((Work > 28) and Not IsLeap) or
     ((work > 29) and IsLeap) then
     begin
       if IsLeap
         Dec(work, 29)
       else
         Dec(work, 28);
       inc(M);
     end;
     if (Work > 31) then
     Begin
      Dec(work, 31);
      Inc(M);
     end;
     if (work > 30) then
     begin
       Inc(M);
       Dec(work, 30);
     end; // april
     if (Work > 31) then
     Begin
      Dec(work, 31);
      Inc(M);
     end;
     if (work > 30) then
     begin
       Inc(M);
       Dec(work, 30);
     end; // June
     if (Work > 31) then
     Begin
      Dec(work, 31);
      Inc(M);
     end;
     if (work > 31) then
     begin
       Inc(M);
       Dec(work, 31);
     end; // Aug
     if (Work > 30) then
     Begin
      Dec(work, 30);
      Inc(M);
     end;
     if (work > 31) then
     begin
       Inc(M);
       Dec(work, 31);
     end; // Oct
     if (Work > 30) then
     Begin
      Dec(work, 30);
      Inc(M);
     end;
     D := Work;
     JultoDateTime := StrtoDate(Pad(IntToStr(M),2)+'/'+Pad(IntToStr(D), 
2)+'/'+IntToStr(Y));
end.
=== End Code ===

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 * Origin: Living in interesting times (1:3005/3)

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