本文是一个php实现的可以用来获取 前一天，后一天的代码示例，HP获取当天起止时间，感兴趣的同学参考下。

date_default_timezone_set('PRC'); //默认时区
echo "今天:",date("Y-m-d",time()),"
 //当天开始时间
 $start_time=strtotime(date("Y-m-d",time()));
 //当天结束时间
 $end_time=$start_time+60*60*24;
echo "今天:",date("Y-m-d",strtotime("18 june 2008")),"";
echo "昨天:",date("Y-m-d",strtotime("-1 day")), "";
echo "明天:",date("Y-m-d",strtotime("+1 day")), "";
echo "一周后:",date("Y-m-d",strtotime("+1 week")), "";
echo "一周零两天四小时两秒后:",date("Y-m-d G:H:s",strtotime("+1 week 2 days 4 hours 2 seconds")), "";
echo "下个星期四:",date("Y-m-d",strtotime("next Thursday")), "";
echo "上个周一:".date("Y-m-d",strtotime("last Monday"))."";
echo "一个月前:".date("Y-m-d",strtotime("last month"))."";
echo "一个月后:".date("Y-m-d",strtotime("+1 month"))."";
echo "十年后:".date("Y-m-d",strtotime("+10 year"))."";
//php判断一个日期距今天还有多少天
echo (strtotime('2023-5-20′)-strtotime(date(“Y-m-d”)))/86400;