date_default_timezone_set('Asia/Hong_Kong');
$startDate = '2015-8-11';
$endDate = '2015-8-31';// 将日期转换为Unix时间戳
$startDateStr = strtotime($startDate);
$endtDateStr = strtotime($endDate);
$total = $endtDateStr-$startDateStr;$now = strtotime(date('Y-m-d'));
$remain = $endtDateStr-$now;echo '为期：'.$total/(3600*24).'天<br>';
echo '剩余：'.$remain/(3600*24).'天';

date_default_timezone_set('Asia/Hong_Kong');
$startTime = '09:00:00';
$endTime = '18:00:00';// 将时间转化为unix时间戳
$startTimeStr = strtotime($startTime);
$endTimeStr = strtotime($endTime);
$total = $endTimeStr - $startTimeStr;$restHours = 1; // 休息1小时

$now = strtotime(date('H:i:s'));
$remain = $endTimeStr - $now;echo '上班时间：'.($total/3600-$restHours).'小时<br>';
echo '还有：'.floor(($remain/3600)).'小时'.floor($remain/60).'分钟下班';

<span id="hour">00</span>小时<span id="minute">00</span>分<span id="second">00</span>秒

 function dealData(id,value){var place = document.getElementById(id);place.innerHTML = value;
}
window.setInterval(function(){ // 每秒从服务器取一次数据var ajax = new Ajax();ajax.get("remain_time.php?a="+Math.random(),function(data){eval("var dtime = "+data); dealData('hour',dtime.hour);dealData('minute',dtime.minute);dealData('second',dtime.second);});
},1000);

date_default_timezone_set('PRC');
$start_time = '09:00:00';
$end_time = '18:00:00';
$start_famate_time = strtotime($start_time);//开始时间转化为时间戳
$end_famate_time = strtotime($end_time); //结束时间转化为时间戳
$now_time = time();
if($end_famate_time < $now_time || $start_time > $now_time){echo '当前不在考试的时间范围内！';exit;
}
$remain_time = $end_famate_time-$now_time; //剩余的秒数
$remain_hour = floor($remain_time/(60*60)); //剩余的小时
$remain_minute = floor(($remain_time - $remain_hour*60*60)/60); //剩余的分钟数
$remain_second = ($remain_time - $remain_hour*60*60 - $remain_minute*60); //剩余的秒数
echo json_encode(array('hour'=>$remain_hour,'minute'=>$remain_minute,'second'=>$remain_second));