Twitter is a social media platform that allows users to create free mini-blogs on which they can make posts of up to 140 characters, called "tweets." You can find out a great deal of information about a Twitter account by viewing a user's profile. A Twitter profile lists the user's name, username, bio, total number of tweets, number of Twitter accounts the user follows, the number of Twitter accounts that follow the user, and the number of Twitter lists the account is listed on. But to find out when a user joined Twitter, you must use the free WhenDidYouJoinTwitter.com tool.
Visit the WhenDidYouJoinTwitter.com home page.
Type your Twitter username in the appropriate field.
Click the "Find out!" button. The site automatically displays the day, month and year that you created your Twitter account.
You can use this tool to find out when other Twitter users created their accounts, as well, not just your own accounts.