Sign in Join
FPDoc Onlineexperiment

YearsBetween function

In unit DateUtils

Calculate the number of whole years between two TDateTime values.

Declaration

pascal
function YearsBetween(const ANow: TDateTime; const AThen: TDateTime; 
 AExact: Boolean=False): Integer

Arguments

ANow

First moment in time.

AThen

Second moment in time.

AExact

Function result

Number of whole years between ANow and AThen.

Description

YearsBetween returns the number of whole years between ANow and AThen. This number is an approximation, based on an average number of days of 365.25 per year (average over 4 years). This means the fractional part of a year is dropped.

See also

Example: ex55

pascal
Program Example55;

{ This program demonstrates the YearsBetween function }

Uses SysUtils,DateUtils;

Procedure Test(ANow,AThen : TDateTime);

begin
 Write('Number of years between ');
 Write(DateToStr(AThen),' and ',DateToStr(ANow));
 Writeln(' : ',YearsBetween(ANow,AThen));
end;

Var
  D1,D2 : TDateTime;

Begin
  D1:=Today;
  D2:=Today-364;
  Test(D1,D2);
  D2:=Today-365;
  Test(D1,D2);
  D2:=Today-366;
  Test(D1,D2);
  D2:=Today-390;
  Test(D1,D2);
  D2:=Today-368;
  Test(D1,D2);
  D2:=Today-1000;
  Test(D1,D2);
End.

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.