Article #16822: How can I determine the week number of a given day in the year?

 Question and Answer Database
FAQ1822D.txt How can I determine the week number of a given day in the year?
Category :Miscellaneous
Platform :All
Product :All 32 bit
Question:
How can I determine the week number of a given day
in the year?
Answer:
This is a highly debated subject, as the first week of the
year may be considered to be before or after Jan 1. The
following function provides a starting point for WeekOfYear
calculations.
Example:
function WeekOfYear(ADate : TDateTime) : word;
var
day : word;
month : word;
year : word;
FirstOfYear : TDateTime;
begin
DecodeDate(ADate, year, month, day);
FirstOfYear := EncodeDate(year, 1, 1);
Result := Trunc(ADate — FirstOfYear) div 7 + 1;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
ShowMessage(IntToStr(WeekOfYear(Date)));
end;
7/16/98 4:31:28 PM

Last Modified: 01-SEP-99