每月的最后一天和每月的第一天(Delphi)

procedure GetMonthDay(const ADate: TDateTime;

var AMonthFirst, AMonthLast: TDateTime);

var

Year, Month, Day: Word;

begin

DecodeDate(ADate, Year, Month, Day);

AMonthFirst := EncodeDate(Year, Month, 1);

if Month + 1 > 12 then

AMonthLast := EncodeDate(Year + 1, 1, 1) - 1

else

AMonthLast := EncodeDate(Year, Month + 1, 1) - 1

end;

procedure GetMonthDay(const ADate: TDateTime;

var AMonthFirst, AMonthLast: TDateTime);

var

Year, Month, Day: Word;

begin

DecodeDate(ADate, Year, Month, Day);

AMonthFirst := EncodeDate(Year, Month, 1);

AMonthLast := EncodeDate(Year, Inc(Month), 1) - 1

end;

每月第一天：Encodedate(year,month,1);

每月最后一天：Encodedate(year,Inc(month),1)-1;

第一天：StrToDate('2000-01-01')

最后一天：strToDate('2000-02-01')-1