add_filter('wplms_email_schedule','my_course_expiry_mail_settings');
function my_course_expiry_mail_settings($args){
if(is_Array($args)){
$args[7]['options']['2160'] = __('Before 3 month of Course expiry','vibe-customtypes');
}
return $args;
}
2160 = number of hours in 3 months