It’s not that easy to save a datetime value in cakephp. For some reason you have to pass it to cakephp as a date string, not as a DateTime and not as a timestamp.

Here is what my code to set the datetime to be 24 hours in the future ended up looking like this:

$u['User']['resetvalidtill'] = date('Y-m-d H:i:s', strtotime("+1 day"));