MonthSpan

Calculate the approximate number of months between two DateTime values.

Declaration

Source position: dateutil.inc line 270

function MonthSpan(

const ANow: TDateTime;

const AThen: TDateTime

):Double;

Arguments

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

Function result

Number (fractions included) of months between ANow and AThen

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).

YearSpan		Calculate the approximate number of years 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.
MonthsBetween		Calculate the number of whole months between two DateTime 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.