How do you check what a person was saying on Twitter a long time ago?

[Annoyingplant567]

Did you know that your tweets have an expiration date on them?

While they never really disappear from your own Twitter stream, they become unsearchable in only a matter of days. At first, Twitter held onto your tweets for around a month, but as the service grew more popular, this "date limit" has dramatically shortened. According to Twitter's search documentation, the current date limit on the search index is "around 1.5 weeks but is dynamic and subject to shrink as the number of tweets per day continues to grow."

You need to use some other strategies to archive tweets if you really need them longer than that.