Subtraction 2 date

[alirezaok]

can anyone write code for subtraction 2 date

example:

$var1=2003/2/10;
$var2=2003/1/5;
$result = $var1 - $var2 ;

(result should is some days)

thanks

[Shrike]

I guess that you want to count the number of days between date 1 and date 2. This isn't as easy as it sounds - here's a snippet i found, can't remember who wriote it though.

	function count_days($dat2,$dat1){
	/* Dat1 and Dat2 passed as "YYYY-MM-DD" */
	  	$tmp_dat1 = mktime(0,0,0,
     		substr($dat1,5,2),substr($dat1,8,2),substr($dat1,0,4));
  		$tmp_dat2 = mktime(0,0,0,
     		substr($dat2,5,2),substr($dat2,8,2),substr($dat2,0,4));

	$yeardiff = date('Y',$tmp_dat1)-date('Y',$tmp_dat2);
  	/* a leap year in every 4 years and the days-difference */
	$diff = date('z',$tmp_dat1)-date('z',$tmp_dat2) +
       		floor($yeardiff /4)*1461;

	/* remainder */
  	for ($yeardiff = $yeardiff % 4; $yeardiff>0; $yeardiff--)
	{
 		$diff += 365 + date('L',
     		mktime(0,0,0,1,1,
           	intval(
         		substr(
               	(($tmp_dat1>$tmp_dat2) ? $dat1 : $dat2),0,4))
       		-$yeardiff+1));
	}

	return $diff;
}

It should factor in stuff like leap years.

[devinemke]

$date1 = '2003/2/10';
$date2 = '2003/1/5';

$result = (strtotime($date1) - strtotime($date2)) / 60 / 60 / 24;
echo "The difference between $date1 and $date2 is $result days";

[Mucello]

That will work, but if your dates are prior to 1970, chances are your PHP build will not support those dates. In that case, you'll need to either come up with a more complicated algorithm or just rely on MySQL to solve it for you.

Here is a sample query:
SELECT TO_DAYS('$endDate') - TO_DAYS('$startDate') as difference;

That will give you the number of days between the two dates.

[devinemke]

...or just rely on MySQL to solve it for you.

who said anything about using mySQL? the original question was just about finding the difference between two dates.

[Mucello]

Originally posted by devinemke
who said anything about using mySQL? the original question was just about finding the difference between two dates.

Just trying to be helpful chief. If it were me asking the question, I would have appreciated anyone's response that was productive. And if you would have read my post, dates prior to 1970 don't work correctly in PHP's strtotime() or date() functions... hence the need to mention MySQL.

[Nixon]

Originally posted by devinemke
who said anything about using mySQL? the original question was just about finding the difference between two dates.

Yeah man, bit out of order there.

[devinemke]

sorry, simply trying to point out that alirezaok, the thread starter, didin't mention mySQL, so i at least am going on the assumption that he/she isn't using mySQL. point well taken regarding strtotime() and dates prior to 1970, however, that is OS dependant. UNIX can hadle negative timestamps whereas Windows cannot.

[Mucello]

I also mentioned it because I know other people use these forums and a lot of people come here searching for solutions previously discussed.

Most UNIX machines that aren't 64 bit running PHP do not handle strtotime() correctly in PHP. Windows is indeed different. We have a 32-bit Unix and strtotime() doesn't work correctly prior to 1970.

I'm done. The end.

[Shrike]

$date1 = '2002-05-01';
$date2 = '2002-12-31';
$result = (strtotime($date2) - strtotime($date1)) / 60 / 60 / 24;
echo "The difference between $date1 and $date2 is $result days";

Result: The difference between 2004-05-01 and 2004-12-31 is 244.041666667 days

:p

[tekky]

how about...

$date1 = '2002-05-01'; 
$date2 = '2002-12-31'; 
$result = (date('z',strtotime($date2)) - (date('z',strtotime($date1))); 
echo "The difference between $date1 and $date2 is $result days";

no decimal values but precise difference in days I would expect

note: this would only work from same year dates obviouslly (it uses Julian dates.... not so useful now that I think about it actually :o

[tekky]

Note: The valid range of a timestamp is typically from Fri, 13 Dec 1901 20:45:54 GMT to Tue, 19 Jan 2038 03:14:07 GMT. (These are the dates that correspond to the minimum and maximum values for a 32-bit signed integer.) Additionally, not all platforms support negative timestamps, therefore your date range may be limited to no earlier than the Unix epoch. This means that e.g. dates prior to Jan 1, 1970 will not work on Windows, some Linux distributions, and a few other operating systems.

Thats where knowing what you work with comes in handy... as the PHP manual specifcally mentions that limitation

Originally posted by Mucello
I also mentioned it because I know other people use these forums and a lot of people come here searching for solutions previously discussed.

Most UNIX machines that aren't 64 bit running PHP do not handle strtotime() correctly in PHP. Windows is indeed different. We have a 32-bit Unix and strtotime() doesn't work correctly prior to 1970.

I'm done. The end.

[Shrike]

Ack what happened there?

[Weedpacket]

You might also want to look at PHP's [man]calendar[/man] functions, in particular the sections on using converting to and from Julian Day fomat; this will give you a range that extends well into the B.Cs. The users notes there provide code for the conversion in the absence of the Calendar module being installed.

[tommynanda]

how about

$date1 = '2002-05-01';  

$date2 = '2002-12-31';  

array1 = explode("-",$date1);
array2 = explode("-",$date2);

$days = abs($array1[2] - $array2[2]);
$month = abs($array1[3]-$array2[3]);
$year = abs($array1[0]-array2[0]);

echo "$year (s) $month (s) $days (s)";

Oops I guess I lost Leap years

Good Luck Anyway
TommYNandA