Get expiration date from provisioning profile certificate data

cert.php

// https://packagist.org/packages/phpseclib/phpseclib
// composer require "phpseclib/phpseclib": "0.3.10"

$certData = base64_decode( OBTAINED_CERTIFICATE_BASE64_STRING_FROM_PLIST  );

$issuer = new File_X509();
$cert = $issuer->loadX509( $certData );

$exirationDate = $cert['tbsCertificate']['validity']['notAfter']['utcTime'];