Error when calculating date in 2006

[BayGirl]

I am sure I am missing something simple.

My problem is this script. It is for a pregnancy ticker. I had no issues when the due date was this year (at any time). WHen the due date became a 2006, one, we had issues. It thinks it has already passed.

Please help!

<?php
$ppd = 355 / 280; //pixels per day
$bim_path = 'jt.gif'; //path to sliding image
$tim_path = 'jb.gif'; //path to ticker image
$bim = imagecreatefromgif($bim_path);
$tim = imagecreatefromgif($tim_path);
$black = imagecolorallocate($tim, 0, 0, 0);
$date = '021806';
$dd = substr($date,2,2);
$mm = substr($date,0,2);
$yy = '20' . substr($date,-2);
if (isset($GET['name']))
$msg = 'Baby ' . $GET['name'] . ' is due on ';
if(!checkdate($mm,$dd,$yy))
$msg = 'Yes, we are trying to have a baby! Wish us luck!';
else
{
$due = mktime(0,0,0,$mm,$dd,$yy);
$now = time();
$diff = date('z',$due) - date('z', $now); //days between now and due date
//moved to here to incorporate other variables into the error messages
$error_msg[1] = 'Human gestation period is approx. 280 days... not ' . $diff;
$error_msg[2] = 'You cannot count down to a birth that has already happened!';
$error_msg[3] = 'Congratulations are in order, the baby is due today!';
$error_msg[4] = 'Congratulations are in order, today you conceived!';
if ($diff > 280)
$error = 1;
else if ($diff < 0)
$error = 2;
else if ($diff == 0)
$error = 3;
else if ($diff == 280)
$error = 4;
if (!$error)
{
$days_left = $diff;
$diff = floor((355-$diff$ppd)+40); //pixel starting location of jt.gif
imagecopy($tim, $bim, floor($diff-23), 0, 0, 0, 41, 59);
if ($_GET['w'] == 1)
$weeks_left = floor($days_left/7);
else
$weeks_left = 0;
$days_left = $days_left-$weeks_left7;
$days_preg = 280-$weeks_left*7-$days_left;
$weeks_preg = floor($days_preg/7);
$days_preg = ($days_preg < 7 ? $days_preg : $days_preg % 7);
unset($msg);
if ($weeks_preg > 0)
$msg = 'We are ' . $weeks_preg . ' week' . ($weeks_preg > 1 ? 's' : '');
if ($days_preg > 0)
{
if (isset($msg))
$msg .= ' & ';
$msg .= $days_preg . ' day' . ($days_preg > 1 ? 's' : '');
}
$msg .= ' pregnant. Only ';
if ($weeks_left > 0)
$msg .= $weeks_left . ($weeks_left > 1 ? ' weeks' : ' week');
if ($days_left)
{
if ($weeks_left > 0)
$msg .= ' and ';
$msg .= $days_left . ($days_left > 1 ? ' days' : ' day');
}
$msg .= ' to go!';
}
else
if ($error)
$msg = $error_msg[$error];
}
imagestring($tim, 3, 2, 6, $msg, $black);
header('Content-type: image/gif');
imagegif($tim);
imagedestroy($tim);
imagedestroy($bim);

[devinemke]

$diff = date('z',$due) - date('z', $now);

i suspect this line is the problem. the "z" switch to the [man]date[/man] function calculates the day of the year starting at 0 for that calender year, so a day next year will reset back to 0 (giving you a negative number the for the $diff). you probably want something more like:

$diff = floor(($due - $now) / 86400);

this will calulate the absolute difference in days between now and the due date.

[BayGirl]

YES!!! It worked! Can i ask WHY it worked? where did the 86400 come from? Thanks so much! I try to understand why things work and why things dont. I knew why mine didn't work, I just didnt know how to properly fix it.

[leatherback]

Hi,

THe dates devin. used are second-based, continuous. So you get the difference in seconds. I suspect the number 86400 is the number of seconds in a day.

J.

[devinemke]

yes, and the [man]floor[/man] fucntion is necessary because the difference might not be a nice round number (due to daylight savings time).

[BayGirl]

got it! Thanks so much. After having my baby my brain has been a frazzled mess! Thanks so much again!