<? /** * 转换为UNIX时间戳 */ function gettime($d) {   if(is_numeric($d))     return $d;   else {     if(! is_string($d)) return 0;     if(ereg(":",$d)) {       $buf = split(" +",$d);       $year = split("[-/]",$buf[0]);       $hour = split(":",$buf[1]);       if(eregi("pm",$buf[2]))         $hour[0] += 12;       return mktime($hour[0],$hour[1],$hour[2],$year[1],$year[2],$year[0]);     }else {       $year = split("[-/]",$d);       return mktime(0,0,0,$year[1],$year[2],$year[0]);     }   } } /** * * DateAdd(interval,number,date) * 返回已添加指定时间间隔的日期。 * Inetrval为表示要添加的时间间隔字符串表达式，例如分或天 * number为表示要添加的时间间隔的个数的数值表达式 * Date表示日期 * * Interval(时间间隔字符串表达式)可以是以下任意值: *  yyyy year年 *  q Quarter季度 *  m Month月 *  y Day of year一年的数 *  d Day天 *  w Weekday一周的天数 *  ww Week of year周 *  h Hour小时 *  n Minute分 *  s Second秒 *  w、y和d的作用是完全一样的，即在目前的日期上加一天，q加3个月，ww加7天。 */ function DateAdd($interval, $number, $date) {   $date = gettime($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 $timestamp; } /** * DateDiff(interval,date1,date2) * 返回两个日期之间的时间间隔 * intervals(时间间隔字符串表达式)可以是以下任意值: *   w  周 *   d  天 *   h  小时 *   n  分钟 *   s  秒 */ function DateDiff ($interval, $date1,$date2) {   // 得到两日期之间间隔的秒数   $timedifference = gettime($date2) - gettime($date1);   switch ($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; } ?> <? // 测试例 $d1 = "2002-01-11"; $d2 = date("Y-m-d",dateadd("d",15,$d1)); echo $d1."的". datediff("d",$d1,$d2)."天后是$d2<br>"; echo $d1."的10天前是".date("Y-m-d",dateadd("d",-10,$d1))."<br>"; $d3 = date("Y/m/d H:i:s"); echo "现在是".$d3."距离2002/2/12 12:59:59还有".datediff("s",$d3,"2002/2/12 12:59:59")."秒<br>"; ?>