How to check if Data X is newer than Data Y?

Question

I have the following variables::
$dt_local: who’s saving comic book value;
$dt_remoto: which is holding value from an external source;
So far so great, I need to compare the two and keep the most current date in the BD, both variables are coming as String.

How can I resolve it more quickly and simply?

Answer 1

Assuming you have these dates in some defined format, you can use the class DateTime of PHP:

$dt_local = DateTime::createFromFormat('d-m-Y', '03-04-2017');
$dt_remoto = DateTime::createFromFormat('d-m-Y', '01-04-2017');

if ($dt_local > $dt_remoto) {
    echo "Local é mais recente", PHP_EOL;
} else if ($dt_local < $dt_remoto) {
    echo "Remoto é mais recente", PHP_EOL;
} else {
    echo "Datas são iguais", PHP_EOL;
}

The exit would be: Local é mais recente.

Whether the date may be in any pattern defined in documentation PHP, use the class constructor itself:

$dt_local = new DateTime('03-04-2017');
$dt_remoto = new DateTime('01-04-2017');

if ($dt_local > $dt_remoto) {
    echo "Local é mais recente", PHP_EOL;
} else if ($dt_local < $dt_remoto) {
    echo "Remoto é mais recente", PHP_EOL;
} else {
    echo "Datas são iguais", PHP_EOL;
}

In theory, any format provided in the table below will be accepted by the application.

Answer 2

One way to check is by using the function max ( $valor1 , $valor2 ) (PHP 4, PHP 5, PHP 7)

where $value1 and $value2 are compatible values in dd/mm/yyyy or dd-mm-yyyy format.

Handbook

<?php
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)));
    }
}

if  (($_POST["dt_local"])&&($_POST["dt_remoto"])){

    $dt_local=inverteData($_POST["dt_local"]);  

    $dt_remoto=inverteData($_POST["dt_remoto"]);

    if ($dt_local!=$dt_remoto){
       $maior = max(array($dt_local,$dt_remoto));
       echo inverteData($maior);
    }else{
       echo "as datas são iguais";;
    } 
}
?>