How to invert dates in PHP, regardless of format?

Question

How to invert dates in PHP? I need to invert dates in PHP regardless of the input format, be YYYY-mm-dd or dd/mm/YYYYY.

Answer 1

Version with explode():

function inverteData($data){
    if(count(explode("/",$data)) > 1){
        return implode("-",array_reverse(explode("/",$data)));
    }elseif(count(explode("-",$data)) > 1){
        return implode("/",array_reverse(explode("-",$data)));
    }
}

Example of use:

$data = "1992-10-01"; //ou 01/10/1992
echo inverteData($data);

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Note: Remembering that this solution works correctly only with the inputs dd/mm/YYYY or YYYY-mm-dd, alternating the result between the two formats.

Answer 2

Instead of using larger functions, you can follow 2 "faster" or "better" paths at my glance.

If you are using some SQL database and want it to return the already formatted date you can use:

SELECT DATE_FORMAT(tbl_data,'%d/%m/%Y') as data FROM tb_tabela

If you want to do the conversion in PHP itself, use :

date('d-m-Y', strtotime($ln['data_cadastro']));

Answer 3

Based on what has been described...

function swap_date($date_str)
{
    if ($date = \DateTime::createFromFormat('Y-m-d', $date_str)) {
        return $date->format('d/m/Y');
    } elseif ($date = \DateTime::createFromFormat('d/m/Y', $date_str)) {
        return $date->format('Y-m-d');
    }

    throw new \InvalidArgumentException('Invalid input date format.');
}

Answer 4

A very elegant solution, in my opinion, created by a fellow Member of the European Parliament revolves around of the solution proposed by Harry Potter just above (or below :p):

/**
 * Altera uma data para outro formato
 * 
 * @param string $date String contendo a data a ser formatada
 * @param string $outputFormat Formato de saida
 * @throws Exception Quando não puder converter a data
 * @return string Data formatada
 * @author Hugo Ferreira da Silva
 */
function parseDate($date, $outputFormat = 'd/m/Y'){
    $formats = array(
        'd/m/Y',
        'd/m/Y H',
        'd/m/Y H:i',
        'd/m/Y H:i:s',
        'Y-m-d',
        'Y-m-d H',
        'Y-m-d H:i',
        'Y-m-d H:i:s',
    );

    foreach($formats as $format){
        $dateObj = DateTime::createFromFormat($format, $date);
        if($dateObj !== false){
            break;
        }
    }

    if($dateObj === false){
        throw new Exception('Invalid date:' . $date);
    }

    return $dateObj->format($outputFormat);
}

In it we can enter the date in any input format and an output format. As long as the format is supported by the class Datetime:

$testDates = array(
    '2012-10-30 00:00:00',
    '06/01/1986 14',
    '06/12/1983 14:30:10',
    '1984-01-06 14:30:10',
);

foreach($testDates as $date){
    echo parseDate($date, 'd/m/Y H:i:s'), PHP_EOL;
}

Demo on PHP Sandbox

---

The solution currently marked as the best response, excuse the frankness, suffers from a serious conceptual problem described in the paradigm of DRY (Don’t Repeat Yourself) that is not something solely aimed at the orientation of objects.

In the solution presented all logic could be reused by using parameterization. It seems complicated because of the profanity (:p), but it is simple, just add another parameter with the separator to be used:

function invertDate( $date, $separator ) {
    return implode( $separator, array_reverse( explode( $separator, $date ) ) );
}

And everything is solved in a single line.

Some say that this simplification is detrimental because despite reversing the date keeps the entry separator.

For these I can make two considerations:

1. If the Application needs to normalize an input, it should theoretically store the normalized input in a single format. In that case, simply change the first occurrence of $separator by a fixed string:

   function invertDate( $date, $separator ) {
       return implode( '/', array_reverse( explode( $separator, $date ) ) );
   }
   

2. If input data accepts multiple input formats, the Application has serious modeling problems and/or lacks data validation.

But it is still possible to improve so that there is no repetition. One of many possibilities would be, after removing the letters from the input, count the number of non-numeric characters in the string and use it as a separator. Here, a coarse code that demonstrates the idea.

The idea is to parse the string to see whichnon- (alpha-)numeric character is most repeated and use it as a separator.

The link code above was not optimized where possible by not treating EVEN the best alternative.

Answer 5

function InvertData($campo){

    if(substr($campo,2,1)=='/'){
        $campo=substr($campo,6,4).'-'.substr($campo,3,2).'-'.substr($campo,0,2);//2012-10-10
    } else {
        $campo=substr($campo,8,2).'/'.substr($campo,5,2).'/'.substr($campo,0,4); //10/10/2012
    }

    return($campo);

}