Command line app to convert to/from UNIX time.

unixtime-converter.php

#!/usr/bin/env php
<?php

if (count($argv) < 2) {
    // Output current UNIX time if no argument specified
    echo time()."\n";
    exit;
}

if (strtolower($argv[1]) == "help") {
    $currentScript = basename($argv[0]);

    echo <<<EOL
Example:
{$currentScript} 1624032013
{$currentScript} "2000-12-25 23:59:59"
{$currentScript} yesterday

EOL;
}
elseif (is_numeric($argv[1])) {
    // Convert from UNIX timestamp
    echo date(DATE_RSS, $argv[1])."\n";
}
else {
    // Convert to UNIX timestamp
    echo strtotime($argv[1])."\n";
}