Unlike Facebook, Twitter doesn't provide historic data to third-parties like Raven. Instead, Raven collects Twitter data daily and stores it in our own database.
Once you've authorized your Twitter account in Raven, you will see your first data point within 24 hours. Raven will update your Twitter data daily from that point forward. If you do not see any data, sit tight and wait it out until our automated processes discover and save that data in your account.