在PHP中是否有一种简单的方法将一种日期格式转换为另一种日期格式?
我有这个:
$old_date = date('y-m-d-h-i-s'); // works
$middle = strtotime($old_date); // returns bool(false)
$new_date = date('Y-m-d H:i:s', $middle); // returns 1970-01-01 00:00:00
但我当然希望它返回当前日期，而不是黎明时分。我做错了什么?
当前回答
我知道这很老了，但是，在遇到一个供应商在他们的api中不一致地使用5种不同的日期格式(并且测试了从5到最新7的各种PHP版本的服务器)时，我决定编写一个适用于无数PHP版本的通用转换器。
这个转换器几乎可以接受任何输入，包括任何标准datetime格式(包括有或没有毫秒)和任何Epoch Time表示(包括有或没有毫秒)，并将其转换为几乎任何其他格式。
称之为:
$TheDateTimeIWant=convertAnyDateTome_toMyDateTime([thedateIhave],[theformatIwant]);
为该格式发送空值将使函数返回Epoch/Unix Time格式的datetime。否则，发送date()支持的任何格式字符串，以及"。u”表示毫秒(我也处理毫秒，即使date()返回0)。
代码如下:
<?php
function convertAnyDateTime_toMyDateTime($dttm,$dtFormat)
{
if (!isset($dttm))
{
return "";
}
$timepieces = array();
if (is_numeric($dttm))
{
$rettime=$dttm;
}
else
{
$rettime=strtotime($dttm);
if (strpos($dttm,".")>0 and strpos($dttm,"-",strpos($dttm,"."))>0)
{
$rettime=$rettime.substr($dttm,strpos($dttm,"."),strpos($dttm,"-",strpos($dttm,"."))-strpos($dttm,"."));
$timepieces[1]="";
}
else if (strpos($dttm,".")>0 and strpos($dttm,"-",strpos($dttm,"."))==0)
{
preg_match('/([0-9]+)([^0-9]+)/',substr($dttm,strpos($dttm,"."))." ",$timepieces);
$rettime=$rettime.".".$timepieces[1];
}
}
if (isset($dtFormat))
{
// RETURN as ANY date format sent
if (strpos($dtFormat,".u")>0) // Deal with milliseconds
{
$rettime=date($dtFormat,$rettime);
$rettime=substr($rettime,0,strripos($rettime,".")+1).$timepieces[1];
}
else // NO milliseconds wanted
{
$rettime=date($dtFormat,$rettime);
}
}
else
{
// RETURN Epoch Time (do nothing, we already built Epoch Time)
}
return $rettime;
}
?>
下面是一些示例调用-您将注意到它还处理任何时区数据(尽管如上所述，在您的时区中返回任何非GMT时间)。
$utctime1="2018-10-30T06:10:11.2185007-07:00";
$utctime2="2018-10-30T06:10:11.2185007";
$utctime3="2018-10-30T06:10:11.2185007 PDT";
$utctime4="2018-10-30T13:10:11.2185007Z";
$utctime5="2018-10-30T13:10:11Z";
$dttm="10/30/2018 09:10:11 AM EST";
echo "<pre>";
echo "<b>Epoch Time to a standard format</b><br>";
echo "<br>Epoch Tm: 1540905011 to STD DateTime ----RESULT: ".convertAnyDateTime_toMyDateTime("1540905011","Y-m-d H:i:s")."<hr>";
echo "<br>Epoch Tm: 1540905011 to UTC ----RESULT: ".convertAnyDateTime_toMyDateTime("1540905011","c");
echo "<br>Epoch Tm: 1540905011.2185007 to UTC ----RESULT: ".convertAnyDateTime_toMyDateTime("1540905011.2185007","c")."<hr>";
echo "<b>Returned as Epoch Time (the number of seconds that have elapsed since 00:00:00 Thursday, 1 January 1970, Coordinated Universal Time (UTC), minus leap seconds.)";
echo "</b><br>";
echo "<br>UTCTime1: ".$utctime1." ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime1,null);
echo "<br>UTCTime2: ".$utctime2." ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime2,null);
echo "<br>UTCTime3: ".$utctime3." ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime3,null);
echo "<br>UTCTime4: ".$utctime4." ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime4,null);
echo "<br>UTCTime5: ".$utctime5." ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime5,null);
echo "<br>NO MILIS: ".$dttm." ----RESULT: ".convertAnyDateTime_toMyDateTime($dttm,null);
echo "<hr>";
echo "<hr>";
echo "<b>Returned as whatever datetime format one desires</b>";
echo "<br>UTCTime1: ".$utctime1." ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime1,"Y-m-d H:i:s")." Y-m-d H:i:s";
echo "<br>UTCTime2: ".$utctime2." ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime2,"Y-m-d H:i:s.u")." Y-m-d H:i:s.u";
echo "<br>UTCTime3: ".$utctime3." ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime3,"Y-m-d H:i:s.u")." Y-m-d H:i:s.u";
echo "<p><b>Returned as ISO8601</b>";
echo "<br>UTCTime3: ".$utctime3." ----RESULT: ".convertAnyDateTime_toMyDateTime($utctime3,"c")." ISO8601";
echo "</pre>";
输出如下:
Epoch Tm: 1540905011 ----RESULT: 2018-10-30 09:10:11
Epoch Tm: 1540905011 to UTC ----RESULT: 2018-10-30T09:10:11-04:00
Epoch Tm: 1540905011.2185007 to UTC ----RESULT: 2018-10-30T09:10:11-04:00
Returned as Epoch Time (the number of seconds that have elapsed since 00:00:00 Thursday, 1 January 1970, Coordinated Universal Time (UTC), minus leap seconds.)
UTCTime1: 2018-10-30T06:10:11.2185007-07:00 ----RESULT: 1540905011.2185007
UTCTime2: 2018-10-30T06:10:11.2185007 ----RESULT: 1540894211.2185007
UTCTime3: 2018-10-30T06:10:11.2185007 PDT ----RESULT: 1540905011.2185007
UTCTime4: 2018-10-30T13:10:11.2185007Z ----RESULT: 1540905011.2185007
UTCTime5: 2018-10-30T13:10:11Z ----RESULT: 1540905011
NO MILIS: 10/30/2018 09:10:11 AM EST ----RESULT: 1540908611
Returned as whatever datetime format one desires
UTCTime1: 2018-10-30T06:10:11.2185007-07:00 ----RESULT: 2018-10-30 09:10:11 Y-m-d H:i:s
UTCTime2: 2018-10-30T06:10:11.2185007 ----RESULT: 2018-10-30 06:10:11.2185007 Y-m-d H:i:s.u
UTCTime3: 2018-10-30T06:10:11.2185007 PDT ----RESULT: 2018-10-30 09:10:11.2185007 Y-m-d H:i:s.u
Returned as ISO8601
UTCTime3: 2018-10-30T06:10:11.2185007 PDT ----RESULT: 2018-10-30T09:10:11-04:00 ISO8601
这个版本中唯一没有的功能是选择希望返回的datetime所在的时区。最初，我写这个代码是为了将任何日期时间更改为Epoch Time，因此，我不需要时区支持。不过，添加起来很简单。
其他回答
试试这个:
$old_date = date('y-m-d-h-i-s');
$new_date = date('Y-m-d H:i:s', strtotime($old_date));
下面是一个将日期转换为不同格式的简单方法。
// Create a new DateTime object
$date = DateTime::createFromFormat('Y-m-d', '2016-03-25');
// Output the date in different formats
echo $date->format('Y-m-d')."\n";
echo $date->format('d-m-Y')."\n";
echo $date->format('m-d-Y')."\n";
为了完整起见，我使用Carbon库添加了一个答案，Carbon库非常常见，在Laravel框架这样的大型项目中使用。
Carbon构造函数可以传递一个日期字符串(任何可以被strtotime()识别的对象)或一个DateTime对象。如果您正在处理一个不容易解析的日期字符串，Carbon提供了Carbon::createFromFormat()静态创建器方法。
$carbon = new Carbon("January 3 2025 4:28 am");
// or
$date = new \DateTime("January 3 2025 4:28 am");
$carbon = new Carbon($date);
// or
$carbon = Carbon::createFromFormat("Y-d-m/H:i", "2025-03-01/04:28");
现在你有了一个原生的Carbon对象，你可以使用Carbon::format()方法以你需要的任何格式输出它:
echo $carbon->format("l jS \\of F Y h:i A");
// Friday 3rd of January 2025 04:28 AM
有很多辅助方法可以快速输出某些格式，例如Carbon::toDateTimeString()，它以MySQL格式输出。
将$date从dd-mm-yyyy hh:mm:ss转换为正确的MySQL datetime 我是这样的:
$date = DateTime::createFromFormat('d-m-Y H:i:s',$date)->format('Y-m-d H:i:s');
$old_date = date('y-m-d-h-i-s'); // works
你在这里做错了，这应该是
$old_date = date('y-m-d h:i:s'); // works
时间分隔符是“:”
我想这会有帮助……
$old_date = date('y-m-d-h-i-s'); // works
preg_match_all('/(\d+)-(\d+)-(\d+)-(\d+)-(\d+)-(\d+)/', $old_date, $out, PREG_SET_ORDER);
$out = $out[0];
$time = mktime($out[4], $out[5], $out[6], $out[2], $out[3], $out[1]);
$new_date = date('Y-m-d H:i:s', $time);
OR
$old_date = date('y-m-d-h-i-s'); // works
$out = explode('-', $old_date);
$time = mktime($out[3], $out[4], $out[5], $out[1], $out[2], $out[0]);
$new_date = date('Y-m-d H:i:s', $time);
