php怎么实现时间转化为秒数

把HH:MM:SS格式的时间字符串转换成秒数，可以使用date_parse函数解析具体的时间信息。
 
<?php
  $time = '21:30:10';
  $parsed = date_parse($time);
  $seconds = $parsed['hour'] * 3600 $parsed['minute'] * 60 $parsed['second'];
  echo $seconds;
?>
 
更详细的例子
 
转换成多少天/多少小时/多少分
 
function get_stay_time($timestamp, $is_hour = 1, $is_minutes = 1)
{
    $CI =& get_instance();
 
    if(empty($timestamp) || $timestamp <= 60) {
        return false;
    }
 
    $time = time();
    $remain_time = $time - $timestamp;
 
    $day = floor($remain_time / (3600*24));
    $day = $day > 0 ? $day.'天' : '';
    $hour = floor(($remain_time % (3600*24)) / 3600);
    $hour = $hour > 0 ? $hour.'小时' : '';
    if($is_hour && $is_minutes) {
        $minutes = floor((($remain_time % (3600*24)) % 3600) / 60);
        $minutes = $minutes > 0 ? $minutes.'分' : '';
        return $day.$hour.$minutes;
    }
 
    if($hour) {
        return $day.$hour;
    }
    return $day;
}