lib/mail/Mail.php
public function setGlobalSendAt($send_at)
    {
        if (!($send_at instanceof SendAt)) {
            $send_at = new SendAt($send_at);
        }
        $this->send_at = $send_at;
    }
public function setGlobalSendAt($send_at)
    {
        if (!($send_at instanceof SendAt)) {
            $send_at = new SendAt($send_at);
        }
        $this->send_at = $send_at;
    }
public function setGlobalSendAt ( $ send_at ) { if ( ! ( $ send_at instanceof SendAt ) ) { $ send_at = new SendAt ( $ send_at ) ; } $ this -> send_at = $ send_at ; }
Add a unix timestamp allowing you to specify when you want your
email to be delivered to a Mail object

Note that timestamps added to Personalization objects override
global timestamps.

@param int|SendAt $send_at A unix timestamp
Add a unix timestamp allowing you to specify when you want your email to be delivered to a Mail object