DateTime类的常见用法

  • 初始化
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//默认为当前时间
$tz = new DateTimezone('Asia/Shanghai');
echo (new DateTime('now', $tz))->format('Y-m-d H:i:s'); //2014-12-04 12:04:55
$d = new DateTime('+1 day', $tz); //2014-12-05 12:04:55

  • 设置时区

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    $d = new DateTime(null, new DateTimezone('Asia/Shanghai'));
    $d->setTimezone('Asia/Shanghai');

  • 设置/获取时间戳

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    echo $d->getTimestamp();  //1417664087
    echo $d->setTimestamp(1417664087)->format('Y-m-d H:i:s');  //2014-12-04 11:34:47

  • 修改时间

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    //明天当前时间 (使用关键字day、week、month year 进行修改)
    使用modify
    echo $d->modify('+1 day')->setTime(0, 0, 0)->format('Y-m-d H:i:s');

或者使用 sub、add

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echo $d->sub(new DateInterval('P1D'))->format('Y-m-d H:i:s');
echo $d->add(new DateInterval('P1D'))->format('Y-m-d H:i:s');

  • 比较日期大小 

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    $t = new DateTimezone('Asia/Shanghai');
    $d1 = new DateTime('2014-12-01', $t);
    $d2 = new DateTime('2014-12-02', $t);
    echo $d1 > $d2 ? 'd1 bigger than d2' : 'd1 less than d2';

  • 获取日期间的差异

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    $diff = $d1->diff($d2);
    print_r($diff);
    DateInterval Object
    (
        [y] => 0
        [m] => 0
        [d] => 1
        [h] => 0
        [i] => 0
        [s] => 0
        [weekday] => 0
        [weekday_behavior] => 0
        [first_last_day_of] => 0
        [invert] => 0
        [days] => 1
        [special_type] => 0
        [special_amount] => 0
        [have_weekday_relative] => 0
        [have_special_relative] => 0
    )