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

# HourSpan

Calculate the approximate number of hours between two TDateTime values.

## Declaration

Source position: dateutil.inc line 288

`function HourSpan(`
`const ANow: TDateTime;`
`const AThen: TDateTime`
`):Double;`

## Arguments

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

## Function result

Number (fractions included) of hours between ANow and AThen

## Description

HourSpan returns the number of Hours between ANow and AThen, including any fractional parts of a Hour.

## See also

YearSpan |  | Calculate the approximate number of years between two TDateTime values.
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.
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.
HoursBetween |  | Calculate the number of whole hours between two TDateTime values.

## Example

    Program Example67;

    { This program demonstrates the HourSpan function }

    Uses SysUtils,DateUtils;

    Procedure Test(ANow,AThen : TDateTime);

    begin
     Write('Number of hours between ');
     Write(DateTimeToStr(AThen),' and ',DateTimeToStr(ANow));
     Writeln(' : ',HourSpan(ANow,AThen));
    end;

    Var
      D1,D2 : TDateTime;

    Begin
      D1:=Now;
      D2:=D1-(59*OneMinute);
      Test(D1,D2);
      D2:=D1-(61*OneMinute);
      Test(D1,D2);
      D2:=D1-(122*OneMinute);
      Test(D1,D2);
      D2:=D1-(306*OneMinute);
      Test(D1,D2);
      D2:=D1-(5.4*OneHour);
      Test(D1,D2);
      D2:=D1-(2.5*OneHour);
      Test(D1,D2);
    End.