Mega Code Archive
Get week number of the year
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Title: Get week number of the year
Try this algorithm:
var
Year, Month, Day: Word;
...
procedure TForm1.Button1Click(Sender: TObject);
var
YourDate, JunFirst: TDateTime;
Week, More, Days: Integer;
DaysLeft: Real;
begin
YourDate:=StrToDate(Edit1.Text);
DecodeDate(YourDate, Year, Month, Day);
JunFirst:=EncodeDate(Year, 1, 1);
case DayOfWeek(YourDate) of
1 : More:=0;
2..7: More:=1;
end;
Days:=Trunc(YourDate-JunFirst)+1;
Week:=(Days div 7)+More;
DaysLeft:=Days mod 7;
case DayOfWeek(JunFirst) of
1 : More:=1;
2..7: More:=9-DayOfWeek(JunFirst);
end;
if (DaysLeft-More>=0) then Week:=Week+1;
Label2.Caption:='Week number '+IntToStr(Week);
end;
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