PHP 日期加减的类，很不错

如何使用这个类呢？请看下面的演示：

$temptime = time(); 
echo strftime ( "%Hh%M %A %d %b" , $temptime ); 
$date = new DateAccount(); 
$temptime = $date ->DateAdd( "n" ,50, $temptime ); 
echo "<p>" ; 
echo strftime ( "%Hh%M %A %d %b" , $temptime );

$temptime = time(); 
echo strftime( "%Hh%M %A %d %b",$temptime); 
$date = new DateAccount(); 
$temptime = $date->DateAdd("n" ,50,$temptime); 
echo "<p>"; 
echo strftime( "%Hh%M %A %d %b",$temptime);

如果一切顺利，你可以看到以下结果：
15h41 Saturday 03 Jun
16h31 Saturday 03 Jun

$currenttime = time(); 
echo "Current time: " . strftime ( "%Hh%M %A %d %b" , $currenttime ). "<br>" ; 
$date = new DateAccount(); 
$newtime = $date ->DateAdd ( "n" ,50 , $currenttime ); 
echo "Time plus 50 minutes: " . strftime ( "%Hh%M %A %d %b" , $newtime ). "<br>" ; 
$temptime = $date ->DateDiff ( "n" , $currenttime , $newtime ); 
echo "Interval between two times: " . $temptime ;

$currenttime = time(); 
echo "Current time: ". strftime("%Hh%M %A %d %b" ,$currenttime)."<br>"; 
$date = new DateAccount(); 
$newtime = $date->DateAdd ("n",50 ,$currenttime); 
echo "Time plus 50 minutes: ". strftime("%Hh%M %A %d %b" ,$newtime)."<br>"; 
$temptime = $date->DateDiff ("n",$currenttime ,$newtime); 
echo "Interval between two times: ".$temptime;

如果一切顺利，你可以看到以下结果：
Current time: 16h23 Saturday 03 Jun
Time plus 50 minutes: 17h13 Saturday 03 Jun
Interval between two times: 50

<?php 
class DateAccount{ 
function __construct(){ 
} 
function DateAdd ( $interval , $number , $date ) { 
$date_time_array = getdate ( $date ); 
$hours = $date_time_array [ "hours" ]; 
$minutes = $date_time_array [ "minutes" ]; 
$seconds = $date_time_array [ "seconds" ]; 
$month = $date_time_array [ "mon" ]; 
$day = $date_time_array [ "mday" ]; 
$year = $date_time_array [ "year" ]; 
switch ( $interval ) { 
case "yyyy" : $year += $number ; break ; 
case "q" : $month +=( $number *3); break ; 
case "m" : $month += $number ; break ; 
case "y" : 
case "d" : 
case "w" : $day += $number ; break ; 
case "ww" : $day +=( $number *7); break ; 
case "h" : $hours += $number ; break ; 
case "n" : $minutes += $number ; break ; 
case "s" : $seconds += $number ; break ; 
} 
$timestamp = mktime ( $hours , $minutes , $seconds , $month , $day , $year ); 
return $timestamp ; 
} 
function DateDiff ( $interval , $date1 , $date2 ) { 
$timedifference = $date2 - $date1 ; 
switch ( $interval ) { 
case "w" : $retval = bcdiv ( $timedifference ,604800); break ; 
case "d" : $retval = bcdiv ( $timedifference ,86400); break ; 
case "h" : $retval = bcdiv ( $timedifference ,3600); break ; 
case "n" : $retval = bcdiv ( $timedifference ,60); break ; 
case "s" : $retval = $timedifference ; break ; 
} 
return $retval ; 
} 
} 
?>