Well, there we are, I've managed to solve the problem I had.
The code is this, where m := month as an integer (1..12) and y := year (2017...) as an integer.
var
m, y: integer;
endDate: TDateTime;
myYear, myMonth, myDay: word;
sd, ed: string;
year, month: string;
begin
year := IntToStr(y);
month := IntToStr(m);
if Length(month) < 2 then
month := '0' + month;
sd := year + '-' + month + '-01';
DecodeDate(endDate, myYear, myMonth, myDay);
ed := year + '-' + month + '-' + IntToStr(myDay);
SQLQuery.Close;
SQLQuery.SQL.Text := 'SELECT * FROM entry WHERE strftime("%Y-%m-%d", date) BETWEEN "' + sd + '" AND "' + ed + '"';
SQLTransaction.Active := True;
SQLQuery.Open;
end;
This now returns all of a calendar months records in my Sqlite database selected on their date. Phew!