mktime() with no arguments should be time()

From the PHP manual on [mktime()](http://php.net/manual/en/function.mktime.php):

> As of PHP 5.1, when called with no arguments, **mktime()** throws an **E_STRICT** notice: use the [time()](http://php.net/manual/en/function.time.php): function instead.

This patch swaps out any call to `mktime()` without arguments for `time()` which prevents E_STRICT errors from occurring.