[Overview][Constants][Procedures and functions][Index] Reference for unit 'DateUtils' (#rtl)

CompareDate

Compare 2 dates, disregarding the time of day

Declaration

Source position: dateutil.inc line 375

function CompareDate(

  const A: TDateTime;

  const B: TDateTime

):TValueRelationship;

Arguments

A

  

First date to compare

B

  

Second date to compare

Function result

A negative number if date A is before B, zero if they are equal, or positive if A is after B.

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

CompareTime

  

Compares two times of the day, disregarding the date part.

CompareDateTime

  

Compare 2 dates, taking into account the time of day

SameDate

  

Check whether two TDateTime values have the same date part.

SameTime

  

Check whether two TDateTime values have the same time part.

SameDateTime

  

Check whether two TDateTime values have the same date and time parts.

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.
Documentation generated on: May 14 2021