PHP wrong result of strtotime

Question

time "24:14" is not valid time and this should be "00:14" for correct valid time but strtotime return CORRECT and its wrong.

    if(strtotime("24:14")) {
        echo "CORRECT<br/>";
    } else {
        echo "NOT CORRECT<br/>";
    }

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Answer 1

You're confused.

strtotime doesn't return true or false. it returns a timestamp, which is a truthy value or false on error.

quoting from the manual:

Returns a timestamp on success, FALSE otherwise. Previous to PHP 5.1.0, this function would return -1 on failure.

Reference -- http://php.net/manual/en/function.strtotime.php

Answer 2

Because it returns false on error, you need to compare it to false

if(strtotime("24:14") !== false) {
    //Correct
} else {
    //Not correct
}

Answer 3

strtotime uses standard PHP time format. As you can see here "24" is a valid string for hours from PHP 5.3.0.

You can use a regex to check that time, for example:

function time_check($t) {
    $reg = '/^([0-9]|0[0-9]|1[0-9]|2[0-3]):[0-5][0-9]$/';
    if ( preg_match($reg, $t) ) 
       echo "CORRENT\n";
    else
       echo "WRONG\n";
}

$check_ok = "01:22";
$check_no = "24:11";

time_check($check_ok);
time_check($check_no);