How to calculate how many days ago in php

/* * $time 需要格式化的时间戳 * return 格式化时间 */ function time_tran($time){ $text = ''; if(!$time){return $text;} $current = time(); $t = $current - $time; $retArr = array('刚刚','秒前','分钟前','小时前','天前','月前','年前'); switch($t){ case $t < 0://时间大于当前时间，返回格式化时间 $text = date('Y-m-d',$time); break; case $t == 0://刚刚 $text = $retArr[0]; break; case $t < 60:// 几秒前 $text = $t.$retArr[1]; break; case $t < 3600://几分钟前 $text = floor($t / 60).$retArr[2]; break; case $t < 86400://几小时前 $text = floor($t / 3600).$retArr[3]; break; case $t < 2592000: //几天前 $text = floor($t / 86400).$retArr[4]; break; case $t < 31536000: //几个月前 $text = floor($t / 2592000).$retArr[5]; break; default : //几年前 $text = floor($t / 31536000).$retArr[6]; } return $text; }