从 DateTime 中减去天数

Question

我就开门见山了。这是我的功能失调代码，它与通过从结束时间减去间隔来找到开始时间有关：

    $timeEnd = "2015-01-08T12:53:13-05:00"; //retrieved from bot crawler
    $interval = date_interval_create_from_date_string("10 days");
    $timeEndOb = new DateTime($timeEnd);
    $timeStartOb = $timeEndOb->sub($interval);
    $timeStart = $timeStartOb->format('Y-m-d H:i:s');
    echo $timeStart;
    //echoing 2015-01-08 12:53:13

我的愚蠢问题是什么？

Answer 1

您只需使用 strtotime 函数和 date 函数就可以做到这一点

$timestamp_end = strtotime("2015-01-08T12:53:13");// Note, I removed the timezone
$date_start = date('Y-m-d H:i:s', strtotime('-10 days', $timestamp_end));
$date_end = date('Y-m-d H:i:s', $timestamp_end);
echo $date_start.' to '.$date_end;

2014-12-29 12:53:13 至 2015-01-08 12:53:13

Answer 2

您可以使用clone克隆对象：

$timeEnd = '2015-01-08T12:53:13-05:00';
$timeEndOb = new DateTime($timeEnd);
$timeStartOb = clone $timeEndOb;
$timeStartOb->modify('-10 days');
echo $timeStart = $timeStartOb->format('c');

demo

或者您可以使用 DateTimeImmutable^PHP>=5.5.0 class 其行为与 DateTime 相同，除了它从不修改自身，而是 returns 一个新对象：

$timeEnd = '2015-01-08T12:53:13-05:00';
$timeEndOb = new DateTimeImmutable($timeEnd);
$timeStartOb = $timeEndOb->modify('-10 days');
echo $timeStart = $timeStartOb->format('c');

demo

从 DateTime 中减去天数

Subtracting days from a DateTime

php

datetime