gistfile1.aw

<?php
/** Store oEmbed results in a transient */
if ( false === ( $tweets = get_site_transient( 'tgm_get_tweets' ) ) {
    $tweets = wp_oembed_get( $url, $args );
    if ( ! $tweets ) // wp_oembed_get returns false on failure
        $tweets = *get your old tweets from here*;
    set_site_transient( 'tgm_get_tweets', $tweets, 60*60*24 );
}