Due to Twitter's API limitations you can only search tweets that are about 1-2 weeks old from inside Wakelet.
This limit varies and sometimes earlier tweets won't appear, so it's best to keep checking back every hour or so. Again, this is due to Twitter itself. If you continue to have issues contact support@wakelet.com.
You can always save older Tweets directly by copying and pasting, or using our iOS and Android apps or browser extension.