Pfthb

The easiest way to do this is

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

You are first giving it the format $dateString is in. Then you are telling it the format you want $newDateString to be in.

This also avoids the use of strtotime, which can be hard to work with at times.

If you are not transforming from one date format to another, but just want the current date (or datetime) in a specific format then it's even easier:

$now = new DateTime();
$timestring = $now->format('Y-m-d h:i:s');

This other question also refers to the same topic: Convert date format yyyy-mm-dd => dd-mm-yyyy.

The Basics

The simplist way to convert one date format into another is to use strtotime() with date(). strtotime() will convert the date into a Unix Timestamp. That Unix Timestamp can then be passed to date() to convert it to the new format.

$timestamp = strtotime('2008-07-01T22:35:17.02');
$new_date_format = date('Y-m-d H:i:s', $timestamp);

Or as a one-liner:

$new_date_format = date('Y-m-d H:i:s', strtotime('2008-07-01T22:35:17.02'));

Keep in mind that strtotime() requires the date to be in a valid format. Failure to provide a valid format will result in strtotime() returning false which will cause your date to be 1969-12-31.

Using DateTime()

As of PHP 5.2, PHP offered the DateTime() class which offers us more powerful tools for working with dates (and time). We can rewrite the above code using DateTime() as so:

$date = new DateTime('2008-07-01T22:35:17.02');
$new_date_format = $date->format('Y-m-d H:i:s');

Working with Unix timestamps

date() takes a Unix timeatamp as its second parameter and returns a formatted date for you:

$new_date_format = date('Y-m-d H:i:s', '1234567890');

DateTime() works with Unix timestamps by adding an @ before the timestamp:

$date = new DateTime('@1234567890');
$new_date_format = $date->format('Y-m-d H:i:s');

If the timestamp you have is in milliseconds (it may end in 000 and/or the timestamp is thirteen characters long) you will need to convert it to seconds before you can can convert it to another format. There's two ways to do this:

• Trim the last three digits off using substr()
  

Trimming the last three digits can be acheived several ways, but using substr() is the easiest:

$timestamp = substr('1234567899000', -3);

• Divide the substr by 1000

You can also convert the timestamp into seconds by dividing by 1000. Because the timestamp is too large for 32 bit systems to do math on you will need to use the BCMath library to do the math as strings:

$timestamp = bcdiv('1234567899000', '1000');

To get a Unix Timestamp you can use strtotime() which returns a Unix Timestamp:

$timestamp = strtotime('1973-04-18');

With DateTime() you can use DateTime::getTimestamp()

$date = new DateTime('2008-07-01T22:35:17.02');
$timestamp = $date->getTimestamp();

If you're running PHP 5.2 you can use the U formatting option instead:

$date = new DateTime('2008-07-01T22:35:17.02');
$timestamp = $date->format('U');

Working with non-standard and ambiguous date formats

Unfortunately not all dates that a developer has to work with are in a standard format. Fortunately PHP 5.3 provided us with a solution for that. DateTime::createFromFormat() allows us to tell PHP what format a date string is in so it can be successfully parsed into a DateTime object for further manipulation.

$date = DateTime::createFromFormat('F-d-Y h:i A', 'April-18-1973 9:48 AM');
$new_date_format = $date->format('Y-m-d H:i:s');

In PHP 5.4 we gained the ability to do class member access on instantiation has been added which allows us to turn our DateTime() code into a one-liner:

$new_date_format = (new DateTime('2008-07-01T22:35:17.02'))->format('Y-m-d H:i:s');

$new_date_format = DateTime::createFromFormat('F-d-Y h:i A', 'April-18-1973 9:48 AM')->format('Y-m-d H:i:s');

Try this:

$old_date = date('y-m-d-h-i-s');
$new_date = date('Y-m-d H:i:s', strtotime($old_date));

To convert $date from dd-mm-yyyy hh:mm:ss to a proper MySQL datetime
I go like this:

$date = DateTime::createFromFormat('d-m-Y H:i:s',$date)->format('Y-m-d H:i:s');

$old_date = date('y-m-d-h-i-s'); // works

you are doing wrong here, this should be

$old_date = date('y-m-d h:i:s'); // works

separator of time is ':'

I think this will help...

$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); 

The following is an easy method to convert dates to different formats.

// 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";

You need to convert the $old_date back into a timestamp, as the date function requires a timestamp as its second argument.

strtotime will work that out. the dates are just not the same and all in us-format.

<?php
$e1 = strtotime("2013-07-22T12:00:03Z");
echo date('y.m.d H:i', $e1);
echo "2013-07-22T12:00:03Z";

$e2 = strtotime("2013-07-23T18:18:15Z");
echo date ('y.m.d H:i', $e2);
echo "2013-07-23T18:18:15Z";

$e1 = strtotime("2013-07-21T23:57:04Z");
echo date ('y.m.d H:i', $e2);
echo "2013-07-21T23:57:04Z";
?>

Try this:

$tempDate = explode('-','03-23-15');
$date = '20'.$tempDate[2].'-'.$tempDate[0].'-'.$tempDate[1];

This native way will help to convert any inputted format to the desired format.

$formatInput = 'd-m-Y'; //Give any format here, this would be converted into your format
$dateInput = '01-02-2018'; //date in above format

$formatOut = 'Y-m-d'; // Your format
$dateOut = DateTime::createFromFormat($formatInput, $dateInput)->format($formatOut);

This solved for me,

$old = '18-04-2018';
$new = date('Y-m-d', strtotime($old));
echo $new;

Output : 2018-04-18

This is the other way you can convert date format

 <?php
$pastDate = "Tuesday 11th October, 2016";
$pastDate = str_replace(",","",$pastDate);

$date = new DateTime($pastDate);
$new_date_format = $date->format('Y-m-d');

echo $new_date_format.' 23:59:59'; ?>

Just using strings, for me is a good solution, less problems with mysql. Detects the current format and changes it if necessary, this solution is only for spanish/french format and english format, without use php datetime function.

class dateTranslator {

 public static function translate($date, $lang) 
 $divider = '';

 if (empty($date))
 return null; 
 
 if (strpos($date, '-') !== false) 
 $divider = '-';
 else if (strpos($date, '/') !== false) 
 $divider = '/';
 
 //spanish format DD/MM/YYYY hh:mm
 if (strcmp($lang, 'es') == 0) 

 $type = explode($divider, $date)[0];
 if (strlen($type) == 4) 
 $date = self::reverseDate($date,$divider);
 
 if (strcmp($divider, '-') == 0) 
 $date = str_replace("-", "/", $date);
 
 //english format YYYY-MM-DD hh:mm
 else 

 $type = explode($divider, $date)[0];
 if (strlen($type) == 2) 

 $date = self::reverseDate($date,$divider);
 
 if (strcmp($divider, '/') == 0) 
 $date = str_replace("/", "-", $date);

 
 
 return $date;
 

 public static function reverseDate($date) 
 $date2 = explode(' ', $date);
 if (count($date2) == 2) 
 $date = implode("-", array_reverse(preg_split("/D/", $date2[0]))) . ' ' . $date2[1];
 else 
 $date = implode("-", array_reverse(preg_split("/D/", $date)));
 

 return $date;
 

USE

dateTranslator::translate($date, 'en')

I know this is old, but, in running into a vendor that inconsistently uses 5 different date formats in their APIs (and test servers with a variety of PHP versions from the 5's through the latest 7's), I decided to write a universal converter that works with a myriad of PHP versions.

This converter will take virtually any input, including any standard datetime format (including with or without milliseconds) and any Epoch Time representation (including with or without milliseconds) and convert it to virtually any other format.

To call it:

$TheDateTimeIWant=convertAnyDateTome_toMyDateTime([thedateIhave],[theformatIwant]);

Sending null for the format will make the function return the datetime in Epoch/Unix Time. Otherwise, send any format string that date() supports, as well as with ".u" for milliseconds (I handle milliseconds as well, even though date() returns zeros).

Here's the code:

 <?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; 
 
 ?>

Here's some sample calls - you will note it also handles any time zone data (though as noted above, any non GMT time is returned in your time zone).

 $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>";

Here's the output:

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

The only thing not in this version is the ability to select the time zone you want the returned datetime to be in. Originally, I wrote this to change any datetime to Epoch Time, so, I didn't need time zone support. It's trivial to add though.