Encode and decode time string in 36 base system

time_hasher.php

<?php

function generate_time($timeString='now'){
	$datetime = new \DateTime($timeString);
	$string = sprintf("%02d-%06d-%08d-%02d",
		mt_rand(0,99),
		$datetime->format('u'),
		(
			$datetime->format('z')*24*60*60
			+ $datetime->format('H')*60*60
			+ $datetime->format('i')*60
			+ $datetime->format('s')
		),
		$datetime->format('y')
	);
	return $string;
}

function encode_time($string) {
	$base36 = strtoupper(base_convert($string, 10, 36));
	return sprintf("%012s", $base36);
}

function decode_time($hash){
	$string = base_convert(strtolower($hash), 36, 10);
	$time = sprintf("%02d %03d, %02d:%02d:%02d.%03d", 
		substr($string, 16, 2),
		(substr($string, 8, 8)/60/60/24),
		(substr($string, 8, 8)/60/60)%24,
		(substr($string, 8, 8)/60)%60,
		substr($string, 8, 8)%60,
		substr($string, 2, 6)
	);
	return \DateTime::createFromFormat('y z, H:i:s.u', $time);
}

for($i=0; $i<10; $i++){
	$datetime = new \DateTime();
	$datetimestring = $datetime->format('Y-m-d H:i:s.u');
	$string = generate_time($datetimestring);
	$hash = encode_time($string);
	$time = decode_time($hash);
	var_dump([
		'input_datetime' => $datetime,
		'input_string' => $string,
		'putput_hash' => $hash,
		'output_datetime' => $time,
		'is_input_same_as_output' => ($datetime == $time),
	]);
	usleep(mt_rand(0,1000));
}