简单粗暴，直接上代码

echo date('Y年 m月 d日 h时:i分:s秒'); // 当前完整时间

echo "昨天:".date("Y-m-d",strtotime("-1 day")), "";

echo "明天:".date("Y-m-d",strtotime("+1 day")). "";

echo "今天:".date("Y-m-d")."";

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"))."";

?>