[Overview][Constants][Procedures and functions][Index] Reference for unit 'dateutils' (#rtl)

# SecondSpan

Calculate the approximate number of seconds between two DateTime values.

## Declaration

Source position: dateutil.inc line 277

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

## Arguments

 ANow First moment in time AThen Second moment in time

## Function result

Number (fractions included) of seconds between ANow and AThen

## Description

SecondSpan returns the number of seconds between ANow and AThen, including any fractional parts of a second.

 YearSpan Calculate the approximate number of years between two DateTime values. 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. MilliSecondSpan Calculate the approximate number of milliseconds between two DateTime values. SecondsBetween Calculate the number of whole seconds between two DateTime values.

## Example

```Program Example69;

{ This program demonstrates the SecondSpan function }

Uses SysUtils,DateUtils;

Procedure Test(ANow,AThen : TDateTime);

begin
Write('Number of seconds between ');
Write(TimeToStr(AThen),' and ',TimeToStr(ANow));
Writeln(' : ',SecondSpan(ANow,AThen));
end;

Var
D1,D2 : TDateTime;

Begin
D1:=Now;
D2:=D1-(999*OneMilliSecond);
Test(D1,D2);
D2:=D1-(1001*OneMilliSecond);
Test(D1,D2);
D2:=D1-(2001*OneMilliSecond);
Test(D1,D2);
D2:=D1-(5001*OneMilliSecond);
Test(D1,D2);
D2:=D1-(5.4*OneSecond);
Test(D1,D2);
D2:=D1-(2.5*OneSecond);
Test(D1,D2);
End.
```