lib/mail/Mail.php
public function setSendAt(
        $send_at,
        $personalizationIndex = null,
        $personalization = null
    ) {
        if (!($send_at instanceof SendAt)) {
            $send_at = new SendAt($send_at);
        }
        if ($personalization != null) {
            $personalization->setSendAt($send_at);
            $this->addPersonalization($personalization);
            return;
        } else {
            if ($this->personalization[0] != null) {
                $this->personalization[0]->setSendAt($send_at);
                return;
            } else if ($this->personalization[$personalizationIndex] != null) {
                $this->personalization[$personalizationIndex]->setSendAt($send_at);
                return;
            } else {
                $personalization = new Personalization();
                $personalization->setSendAt($send_at);
                if (($personalizationIndex != 0)
                    && ($this->getPersonalizationCount() <= $personalizationIndex)
                ) {
                    $this->personalization[$personalizationIndex] = $personalization;
                } else {
                    $this->addPersonalization($personalization);
                }
                return;
            }
        }
    }
public function setSendAt(
        $send_at,
        $personalizationIndex = null,
        $personalization = null
    ) {
        if (!($send_at instanceof SendAt)) {
            $send_at = new SendAt($send_at);
        }
        if ($personalization != null) {
            $personalization->setSendAt($send_at);
            $this->addPersonalization($personalization);
            return;
        } else {
            if ($this->personalization[0] != null) {
                $this->personalization[0]->setSendAt($send_at);
                return;
            } else if ($this->personalization[$personalizationIndex] != null) {
                $this->personalization[$personalizationIndex]->setSendAt($send_at);
                return;
            } else {
                $personalization = new Personalization();
                $personalization->setSendAt($send_at);
                if (($personalizationIndex != 0)
                    && ($this->getPersonalizationCount() <= $personalizationIndex)
                ) {
                    $this->personalization[$personalizationIndex] = $personalization;
                } else {
                    $this->addPersonalization($personalization);
                }
                return;
            }
        }
    }
public function setSendAt ( $ send_at , $ personalizationIndex = null , $ personalization = null ) { if ( ! ( $ send_at instanceof SendAt ) ) { $ send_at = new SendAt ( $ send_at ) ; } if ( $ personalization != null ) { $ personalization -> setSendAt ( $ send_at ) ; $ this -> addPersonalization ( $ personalization ) ; return ; } else { if ( $ this -> personalization [ 0 ] != null ) { $ this -> personalization [ 0 ] -> setSendAt ( $ send_at ) ; return ; } else if ( $ this -> personalization [ $ personalizationIndex ] != null ) { $ this -> personalization [ $ personalizationIndex ] -> setSendAt ( $ send_at ) ; return ; } else { $ personalization = new Personalization ( ) ; $ personalization -> setSendAt ( $ send_at ) ; if ( ( $ personalizationIndex != 0 ) && ( $ this -> getPersonalizationCount ( ) <= $ personalizationIndex ) ) { $ this -> personalization [ $ personalizationIndex ] = $ personalization ; } else { $ this -> addPersonalization ( $ personalization ) ; } return ; } } }
Add a unix timestamp allowing you to specify when you want your
email to be delivered to a Personalization or Mail object

If you don't provide a Personalization object or index, the
send at timestamp will be global to entire message. Note that
timestamps added to Personalization objects override
global timestamps.

@param int|SendAt $send_at A unix timestamp
@param int|null $personalizationIndex Index into an array of
existing Personalization
objects
@param Personalization|null $personalization A pre-created
Personalization object
Add a unix timestamp allowing you to specify when you want your email to be delivered to a Personalization or Mail object