# Difference in days between two dates

Hi Folks,

I have two dates.  For example, 07/04/1990 and 25/12/2002 (as you can see, they're in the format of DD/MM/YYYY).  I need to find out how many DAYS have passed since the first date to the second date.

I'm sure there's an easy way of doing this, it's just I can't be bothered thinking about it tonight :)

Thanks,

Stu
LVL 6
###### Who is Participating?

x

Commented:
convert it to tdatetime
(there are various functions to do this)
and then just take the difference

count of days:= date2-date1;

(sorry no delphi on hand,
therfore no sample,
but so it goes in theory)

meikl ;-)
0

Author Commented:
Oh yeah, if 50 points ain't enough, I'll up it.  I think this is an easy Q., but if it's not, I'm happy to double or triple it.

Stu
0

Commented:
appendix,
the result will be of double-type,
just use trunc to transform the
result into an integer
0

Commented:
straight from my website (www.drdelphi.com)

var yesterday,today:Tdatetime;
dayspassed:integer;
begin
today:=strtodate('05/28/1998');
yesterday:=strtodate('05/27/1998');
dayspassed:=(round(today))-(round(yesterday));
showmessage(inttostr(dayspassed));
{Notice that we use the round function here..
This is to get the numbers of DAYS.. if we were looking for the
fractional part of the day as well, we would use a real datatype
for dayspassed and showmessage as FloatTostr(daypassed)}

end;

Good luck!!

0

Commented:
If you are using Delphi6 declare dateutils on your uses clause... on this unit you will find lots of interesting procedures for date handling!
Such as:

function IsInLeapYear(const AValue: TDateTime): Boolean;
function IsPM(const AValue: TDateTime): Boolean;
function IsValidDate(const AYear, AMonth, ADay: Word): Boolean;
function IsValidTime(const AHour, AMinute, ASecond, AMilliSecond: Word): Boolean;
function IsValidDateTime(const AYear, AMonth, ADay, AHour, AMinute, ASecond,
AMilliSecond: Word): Boolean;
function IsValidDateDay(const AYear, ADayOfYear: Word): Boolean;
function IsValidDateWeek(const AYear, AWeekOfYear,                    {ISO 8601}
function IsValidDateMonthWeek(const AYear, AMonth, AWeekOfMonth,     {ISO 8601x}
function WeeksInYear(const AValue: TDateTime): Word;                  {ISO 8601}
function WeeksInAYear(const AYear: Word): Word;                       {ISO 8601}
function DaysInYear(const AValue: TDateTime): Word;
function DaysInAYear(const AYear: Word): Word;
function DaysInMonth(const AValue: TDateTime): Word;
function DaysInAMonth(const AYear, AMonth: Word): Word;
function Today: TDateTime;
function Yesterday: TDateTime;
function Tomorrow: TDateTime;
function IsToday(const AValue: TDateTime): Boolean;
function IsSameDay(const AValue, ABasis: TDateTime): Boolean;

Hope it helps!
VSF
www.victory.hpg.com.br
0

Author Commented:
Hi Meikl,

Thanks heaps :)  Worked a treat.

Thanks to everyone else too for you quick responses!

Stu
0

Author Commented:
DrDelphi,

Meikl's code was the first posted that solved the problem, but it was yours that I actually used.  So, in all fairness, here's some points for you as well.  Thanks a lot!

http://www.experts-exchange.com/jsp/qManageQuestion.jsp?ta=delphi&qid=20293500

Cheers,

Stu
0
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