php DateTime 类

<?php
$date = new DateTime();
echo $date->format('Y-m-d H:i:s');
echo "<br/>";

//2、获取特定时间并打印
$date = new DateTime('2014-07-04 23:59:59');
echo $date->format('Y-m-d H:i:s');
echo "<br/>";
$date2 = new DateTime('tomorrow');
echo $date2->format('Y-m-d H:i:s');
echo "<br/>";
$date2 = new DateTime('+2 days');
echo $date2->format('Y-m-d H:i:s');
echo '<hr/>';

$date = new DateTime();
// modify方法
$date->modify('+1 day');
echo $date->format('Y-m-d H:i:s');
echo "<br/>";

// setDate方法
$date->setDate('1989','10','10');
echo $date->format('Y-m-d H:i:s');
echo "<br/>";

// setTime方法
$date = new DateTime('2010-01-01');

$date->setTime(14, 55);
echo $date->format('Y-m-d H:i:s') . "<br/>";

$date->setTime(14, 55, 24);
echo $date->format('Y-m-d H:i:s') . "<br/>";

//3. unix时间戳的转换
//获取当前时间的时间戳
$date = new DateTime();
echo $date->format('U');
echo "<br/>";
//或者
$date = new DateTime();
echo $date->getTimestamp();
echo "<br/>";

//将时间戳转换为可读时间
//
$date = new DateTime('@1536547854');

$date->setTimezone(new DateTimeZone('Asia/Shanghai'));
echo $date->format('Y-m-d H:i:s');
echo "<br/>";

//或者
$date = new DateTime();
$date->setTimestamp(1536547854);
echo $date->format('Y-m-d H:i:s');
echo "<br/>";

//4. 日期的比较
//日期大小比较
$date1 = new DateTime();
$date2 = new DateTime('2016-12-15');

if($date1 < $date2) {
    echo $date2->format('Y-m-d H:i:s') . ' is in the future';
}

///日期间隔
$date1 = new DateTime();
$date2 = new DateTime('2020-10-15');

$diff = $date1->diff($date2);
//print_r($diff);
//格式化输出
echo $diff->format("The future will come in %Y years %m months and %d days");