Reference for package '#rtl'

CompareDate

Compare 2 dates, disregarding the time of day

Declaration

Source position: dateutil.inc line 362

  function CompareDate(const A: TDateTime; const B: TDateTime)
                       : TValueRelationship;

Description

CompareDate compares the date parts of two timestamps A and B and returns the following results:

< 0
if the day part of A is earlier than the day part of B.
0
if A and B are the on same day (times may differ) .
> 0
if the day part of A is later than the day part of B.

See also

Name Description
CompareDateTime Compare 2 dates, taking into account the time of day
CompareTime Compares two times of the day, disregarding the date part.
SameDate Check whether two TDateTime values have the same date part.
SameDateTime Check whether two TDateTime values have the same date and time parts.
SameTime Check whether two TDateTime values have the same time part.

Example

Program Example99;
{ This program demonstrates the CompareDate function }
Uses SysUtils,DateUtils;
Const
  Fmt = 'dddd dd mmmm yyyy';
Procedure Test(D1,D2 : TDateTime);
Var
  Cmp : Integer;
begin
  Write(FormatDateTime(Fmt,D1),' is ');
  Cmp:=CompareDate(D1,D2);
  If Cmp<0 then
    write('earlier than ')
  else if Cmp>0 then
    Write('later than ')
  else
    Write('equal to ');
  Writeln(FormatDateTime(Fmt,D2));
end;
Var
  D,N : TDateTime;
Begin
  D:=Today;
  N:=Now;
  Test(D,D);
  Test(N,N);
  Test(D+1,D);
  Test(D-1,D);
  Test(D+OneSecond,D);
  Test(D-OneSecond,D);
  Test(N+OneSecond,N);
  Test(N-OneSecond,N);
End.