我显示版权的方式，它会自动更新

<p class="text-muted credit">Copyright &copy;
    <?php
        $copyYear = 2017; // Set your website start date
        $curYear = date('Y'); // Keeps the second year updated
        echo $copyYear . (($copyYear != $curYear) ? '-' . $curYear : '');
    ?> 
</p>    

它将输出结果为

copyright @ 2017   //if $copyYear is 2017 
copyright @ 2017-201x    //if $copyYear is not equal to Current Year.

适用于php 5.4+版本

<?php
    $current= new \DateTime();
    $future = new \DateTime('+ 1 years');

    echo $current->format('Y'); 
    //For 4 digit ('Y') for 2 digit ('y')
?>

或者你可以把它用在一行上

$year = (new DateTime)->format("Y");

如果你想增加或减少一年另一个方法;添加修改行如下所示。

<?PHP 
  $now   = new DateTime;
  $now->modify('-1 years'); //or +1 or +5 years 
  echo $now->format('Y');
  //and here again For 4 digit ('Y') for 2 digit ('y')
?>

在date函数的第二个参数中可以得到更多的值 Strtotime返回参数传递的时间戳

// This work when you get time as string
echo date('Y', strtotime("now"));

// Get next years
echo date('Y', strtotime("+1 years"));

// 
echo strftime("%Y", strtotime("now"));

使用datetime类

echo (new DateTime)->format('Y');

http://us2.php.net/date

echo date('Y');

print date('Y');

有关更多信息，请查看date()函数文档:https://secure.php.net/manual/en/function.date.php

用M打印当前月份，用D打印日期，用Y打印年份。

<?php echo date("M D Y"); ?>