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    YearSpan

    Calculate the approximate number of years between two TDateTime values.

    Declaration

    Source position: dateutil.inc line 294

    function YearSpan(const ANow: TDateTime; const AThen: TDateTime)
                  : Double;

    Arguments

    Name Description
    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).

    See also

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