Reference for package '#rtl'

MonthSpan

Calculate the approximate number of months between two TDateTime values.

Declaration

Source position: dateutil.inc line 272

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

Description

MonthSpan returns the number of month between ANow and AThen, including any fractional parts of a month. This number is an approximation, based on an average number of days of 30.4375 per month (average over 4 years).

See also

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

Example

Program Example64;
{ This program demonstrates the MonthSpan function }
Uses SysUtils,DateUtils;
Procedure Test(ANow,AThen : TDateTime);
begin
 Write('Number of months between ');
 Write(DateToStr(AThen),' and ',DateToStr(ANow));
 Writeln(' : ',MonthSpan(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.