Date format

From: Martin Brooks <martin@image-data.com>

I have a very urgent problem i am currently working on a college project

where i have to check the validity of dates entered into a maskedit in

this format - __/__/____ e.g. 12/12/1997.

Ages ago, I did a very silly date encoder/decoder that did check that a date was valid. See code below.

function CheckDateFormat(SDate:string):string;

var

IDateChar:string;

x,y:integer;

begin

IDateChar:='.,\/';

for y:=1 to length(IDateChar) do

begin

x:=pos(IDateChar[y],SDate);

while x>0 do

begin

Delete(SDate,x,1);

Insert('-',SDate,x);

x:=pos(IDateChar[y],SDate);

end;

end;

CheckDateFormat:=SDate;

end;

function DateEncode(SDate:string):longint;

var

year,month,day:longint;

wy,wm,wd:longint;

Dummy:TDateTime;

Check:integer;

begin

DateEncode:=-1;

SDate:=CheckDateFormat(SDate);

Val(Copy(SDate,1,pos('-',SDate)-1),day,check);

Delete(Sdate,1,pos('-',SDate));

Val(Copy(SDate,1,pos('-',SDate)-1),month,check);

Delete(SDate,1,pos('-',SDate));

Val(SDate,year,check);

wy:=year;

wm:=month;

wd:=day;

try

Dummy:=EncodeDate(wy,wm,wd);

except

year:=0;

month:=0;

day:=0;

end;

DateEncode:=(year*10000)+(month*100)+day;

end;

DateSer Function

From: "Damir Bulic - Ramayana" <damir.bulic@zg.tel.hr>

Hi, this is a source of a function DateSer I wrote, because I worked in VB before, and this was a very useful function. Delphi unfortunately doesn't have it. Use it in a form of

DecodeDate(Date,y,m,d);

NewDate:=DateSer(y-4,m+254,d+1234);

or something like that....

function DateSer(y,m,d: Integer): TDateTime;

const

mj: array[1..12] of Integer=(31,28,31,30,31,30,31,31,30,31,30,31);

var

add: Integer;

begin

while(true) do begin

y:=y+(m-1) div 12;

m:= (m-1) mod 12 +1;

if m<=0 then begin

Inc(m,12);

Dec(y);

end;

if ((y mod 4 = 0) and

((y mod 100<>0) or (y mod 400=0)))

and (m=2) then

add:=1 //add one day in February

else

add:=0;

if (d>0) and (d<=(mj[m]+add)) then break;

if d>0 then begin Dec(d,mj[m]+add); Inc(m); end

else begin Inc(d,mj[m]+add); Dec(m); end;

end;

Result:=EncodeDate(y,m,d);

end;

Automatic Year in a date edit

"Henk Schreij" <schreij@daxis.nl>

Als je een Datumveld intypt in een Database, dan kun je het jaartal weglaten, omdat de computer die voor je invult met het huidige jaar. Kan zoiets ook in een gewoon Edit-veld?

Het antwoord is ja, dat kan met:

PROCEDURE TForm1.Edit1Exit(Sender: TObject);

BEGIN

IF Edit1.Text<>'' THEN BEGIN

TRY

StrToDate(Edit1.Text);

EXCEPT

Edit1.SetFocus;

MessageBeep(0);

raise Exception.Create('"'+Edit1.Text

+'" is no valid Date');

END{try};

Edit1.Text:=DateToStr(StrToDate(Edit1.Text));

END{if};

END;