YearSpan

Calculate the approximate number of years between two DateTime values.

Declaration

Source position: dateutil.inc line 269

function YearSpan(

const ANow: TDateTime;

const AThen: TDateTime

):Double;

Arguments

`ANow`		First moment in time
`AThen`		Second moment in time

Function result

Number (fractions included) of years between ANow and AThen

Description

YearSpan returns the number of years between ANow and AThen, including any fractional parts of a year. This number is an approximation, based on an average number of days of 365.25 per year (average over 4 years).

MonthSpan		Calculate the approximate number of months between two DateTime values.
WeekSpan		Calculate the approximate number of weeks between two DateTime values.
DaySpan		Calculate the approximate number of days between two DateTime values.
HourSpan		Calculate the approximate number of hours between two DateTime values.
MinuteSpan		Calculate the approximate number of minutes between two DateTime values.
SecondSpan		Calculate the approximate number of seconds between two DateTime values.
MilliSecondSpan		Calculate the approximate number of milliseconds between two DateTime values.
YearsBetween		Calculate the number of whole years between two DateTime values

Example

Program Example63;

{ This program demonstrates the YearSpan function }

Uses SysUtils,DateUtils;

Procedure Test(ANow,AThen : TDateTime);

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