使用strtotime()和date():

$original_dateTime = "2019-05-11 17:02:07"; #This may be database datetime
$newDate = date("d-m-Y", strtotime($original_dateTime));

随着时间的推移

$newDate = date("d-m-Y h:i:s a", strtotime($original_dateTime));

$timestamp = strtotime(your date variable); 
$new_date = date('d-m-Y', $timestamp);

有关更多信息，请参阅strtotime的文档。

或者更短:

$new_date = date('d-m-Y', strtotime(your date variable));

Note: Because this post's answer sometimes gets upvoted, I came back here to kindly ask people not to upvote it anymore. My answer is ancient, not technically correct, and there are several better approaches right here. I'm only keeping it here for historical purposes. Although the documentation poorly describes the strtotime function, @rjmunro correctly addressed the issue in his comment: it's in ISO format date "YYYY-MM-DD". Also, even though my Date_Converter function might still work, I'd like to warn that there may be imprecise statements below, so please do disregard them.

投票最多的答案其实是错误的!

PHP strtotime手册在这里声明“该函数期望得到一个包含英文日期格式的字符串”。它实际上的意思是，它期望美国日期格式，如“m-d-Y”或“m/d/Y”。

这意味着以“Y-m-d”形式提供的日期可能会被strtotime错误解释。您应该以预期的格式提供日期。

我写了一个小函数，以几种格式返回日期。随意使用和修改。如果有人真的把它变成了一个类，我很高兴它能被分享。

function Date_Converter($date, $locale = "br") {

    # Exception
    if (is_null($date))
        $date = date("m/d/Y H:i:s");

    # Let's go ahead and get a string date in case we've
    # been given a Unix Time Stamp
    if ($locale == "unix")
        $date = date("m/d/Y H:i:s", $date);

    # Separate Date from Time
    $date = explode(" ", $date);

    if ($locale == "br") {
        # Separate d/m/Y from Date
        $date[0] = explode("/", $date[0]);
        # Rearrange Date into m/d/Y
        $date[0] = $date[0][1] . "/" . $date[0][0] . "/" . $date[0][2];
    }

    # Return date in all formats
        # US
        $Return["datetime"]["us"] = implode(" ", $date);
        $Return["date"]["us"]     = $date[0];

        # Universal
        $Return["time"]           = $date[1];
        $Return["unix_datetime"]  = strtotime($Return["datetime"]["us"]);
        $Return["unix_date"]      = strtotime($Return["date"]["us"]);
        $Return["getdate"]        = getdate($Return["unix_datetime"]);

        # BR
        $Return["datetime"]["br"] = date("d/m/Y H:i:s", $Return["unix_datetime"]);
        $Return["date"]["br"]     = date("d/m/Y", $Return["unix_date"]);

    # Return
    return $Return;

} # End Function

如果你想避免strtotime转换(例如，strtotime不能解析你的输入)，你可以使用，

$myDateTime = DateTime::createFromFormat('Y-m-d', $dateString);
$newDateString = $myDateTime->format('d-m-Y');

或者,相当于:

$newDateString = date_format(date_create_from_format('Y-m-d', $dateString), 'd-m-Y');

你首先给它$dateString的格式。然后你告诉它你想要的$newDateString的格式。

或者如果source-format总是“Y-m-d”(yyyy-mm-dd)，那么只需使用DateTime:

<?php
    $source = '2012-07-31';
    $date = new DateTime($source);
    echo $date->format('d.m.Y'); // 31.07.2012
    echo $date->format('d-m-Y'); // 31-07-2012
?>

在PHP中，任何日期都可以转换为所需的日期格式，使用不同的场景，例如将任何日期格式转换为 日、日、月、年

$newdate = date("D, d M Y", strtotime($date));

它将以以下非常好的格式显示日期

2020年11月16日星期一

使用此函数可以从任何格式转换为任何格式

function reformatDate($date, $from_format = 'd/m/Y', $to_format = 'Y-m-d') {
    $date_aux = date_create_from_format($from_format, $date);
    return date_format($date_aux,$to_format);
}