Title: Getting the dates of the first and last day of the month of a given date
Question: How can I get the dates of the first and last day of the month of a given date?
Answer:
FDOM and LDOM
-------------
FDOM returns the date that corresponds to the first day of the same
month as the date passed as parameter, while LDOM returns the date
that corresponds to the last day of the month (subtracting 1 from
the date that corresponds to the first day of the next month).
function FDOM(Date: TDateTime): TDateTime;
var
Year, Month, Day: Word;
begin
DecodeDate(Date, Year, Month, Day);
Result := EncodeDate(Year, Month, 1);
end;
function LDOM(Date: TDateTime): TDateTime;
var
Year, Month, Day: Word;
begin
DecodeDate(Date, Year, Month, Day);
if Month else begin Month := 1; inc(Year) end;
Result := EncodeDate(Year, Month, 1) - 1;
end;
Sample call
-----------
procedure TForm1.Button1Click(Sender: TObject);
begin
ShowMessage(DateToStr(FDOM(Now)));
ShowMessage(DateToStr(LDOM(Now)));
end;