function pleac_Adding_to_or_Subtracting_from_a_Date()
{
// Date arithmetic is probably most easily performed using timestamps [i.e. *NIX Epoch
// Seconds]. Dates - in whatever form - are converted to timestamps, these are
// arithmetically manipulated, and the result converted to whatever form required.
// Note: use 'mktime' to create timestamps properly adjusted for daylight saving; whilst
// 'strtotime' is more convenient to use, it does not, AFAIK, include this adjustment
$when = $now + $difference;
$then = $now - $difference;
// ------------
$now = mktime(0, 0, 0, 8, 6, 2003);
$diff1 = dateOffset('day=1');
$diff2 = dateOffset('weeks=2');
echo 'Today is: ' . date('Y-m-d', $now) . "\n";
echo 'One day in the future is: ' . date('Y-m-d', $now + $diff1) . "\n";
echo 'Two weeks in the past is: ' . date('Y-m-d', $now - $diff2) . "\n";
// ----------------------------
// Date arithmetic performed using a custom function, 'dateOffset'. Internally, offset may
// be computed in one of several ways:
// * Direct timestamp manipulation - fastest, but no daylight saving adjustment
// * Via 'date' built-in function - slower [?], needs a base time from which to
// compute values, but has daylight saving adjustment
// * Via 'strtotime' built-in function - as for 'date'
// * Via 'DateTime' class
//
// Approach used here is to utilise direct timestamp manipulation in 'dateOffset' [it's
// performance can also be improved by replacing $tbl with a global definition etc],
// and to illustrate how the other approaches might be used
// 1. 'dateOffset'
$birthtime = mktime(3, 45, 50, 1, 18, 1973);
$interval = dateOffset('day=55', 'hours=2', 'min=17', 'sec=5');
$then = $birthtime + $interval;
printf("Birthtime is: %s\nthen is: %s\n", date(DATE_RFC1123, $birthtime), date(DATE_RFC1123, $then));
// ------------
// 2. 'date'
// Base values, and offsets, respectively
$hr = 3;
$min = 45;
$sec = 50;
$mon = 1;
$day = 18;
$year = 1973;
$yroff = 0;
$monoff = 0;
$dayoff = 55;
$hroff = 2;
$minoff = 17;
$secoff = 5;
// Base date
$birthtime = mktime($hr, $min, $sec, $mon, $day, $year, TRUE);
$year = date('Y', $birthtime) + $yroff;
$mon = date('m', $birthtime) + $monoff;
$day = date('d', $birthtime) + $dayoff;
$hr = date('H', $birthtime) + $hroff;
$min = date('i', $birthtime) + $minoff;
$sec = date('s', $birthtime) + $secoff;
// Offset date
$then = mktime($hr, $min, $sec, $mon, $day, $year, TRUE);
printf("Birthtime is: %s\nthen is: %s\n", date(DATE_RFC1123, $birthtime), date(DATE_RFC1123, $then));
// ------------
// 3. 'strtotime'
// Generate timestamp whatever way is preferable
$birthtime = mktime(3, 45, 50, 1, 18, 1973);
$birthtime = strtotime('1/18/1973 03:45:50');
$then = strtotime('+55 days 2 hours 17 minutes 2 seconds', $birthtime);
printf("Birthtime is: %s\nthen is: %s\n", date(DATE_RFC1123, $birthtime), date(DATE_RFC1123, $then));
// ------------
// 4. 'DateTime' class
$birthtime = new DateTime('1/18/1973 03:45:50');
$then = new DateTime('1/18/1973 03:45:50');
$then->modify('+55 days 2 hours 17 minutes 2 seconds');
printf("Birthtime is: %s\nthen is: %s\n", $birthtime->format(DATE_RFC1123), $then->format(DATE_RFC1123));
}
require_once "PHP/Framework.php";
// Core framework
require_once "PHP/Utils.php";
// Helper Tools
/* Fix Input Variables */
if (!isset($_REQUEST['Camera'])) {
$_REQUEST['Camera'] = "";
}
if (!isset($_REQUEST['date']) || $_REQUEST['date'] == "") {
$_REQUEST['date'] = date("Y-m-d");
}
/* Init the Page, and register core template variables */
$Page = new Page();
$Page->setField(array("CAMERA" => $_REQUEST['Camera'], "DATE_CUR" => $_REQUEST['date']));
/* Current Request */
$Page->setField(array("DATE_NEXT" => dateOffset($_REQUEST['date'], "+1 day"), "DATE_PREV" => dateOffset($_REQUEST['date'], "-1 day")));
/* Date Next/Prev */
///////////////////////////////////////////////////////
/* DVR_Engine Class */
///////////////////////////////////////////////////////
class DVR_Engine
{
private static $baseFolder, $snapFolder;
var $camList;
function __construct($baseFolder, $snapFolder)
{
if (!file_exists($baseFolder) || !file_exists($snapFolder)) {
Framework::debug(DEBUG_FATAL, "Failed to create DVR_Engine class - Specified folders do not exist!\nBase Folder: {$baseFolder}\nSnap Folder: {$snapFolder}\n");
}
$this->baseFolder = $baseFolder;
$this->snapFolder = $snapFolder;
