相对时间函数

gistfile1.php

<?php
function rtime($time = false, $limit = 86400, $format = 'Y-m-d H:i') 
{
    if(empty($time)||(!is_string($time)&& !is_numeric($time)))
        $time = time();
    elseif (is_string($time)) 
        $time = strtotime($time);

    $now = time();
    $relative = '';

    if($time === $now) $relative = '刚刚';
    elseif($time > $now) $relative = '即将';
    else 
    {
        $diff = $now - $time;
        if($diff >= $limit) $relative = date($format, $time);
        elseif($diff < 60) 
        {
            $relative = '不到1分钟';
        }
        elseif(($minutes = ceil($diff/60)) < 60)
        {
            $relative = $minutes.'分钟'.'前';
        }
        elseif(($hours = ceil($diff/3600)) < 24*3)
        {
            $relative = $hours.'小时前';
        }
        else
        {
            $days = ceil($diff/(3600*24));
            $relative = $days.'天前';
        }
    }

    return $relative;
}