Update: Due to a change in the Facebook data stream, this interactive no longer works for all users.
Facebook will celebrate its 10th birthday next week. Created in a dorm room by Mark Zuckerberg and a few friends, TheFacebook.com came to life on Feb. 4, 2004. In its decade of existence, the social network has attracted 1.1 billion users, and all their pokes, wall posts, baby photos and engagement announcements add up to a whole lot of time. Use TIME’s calculator to see just how many days of your life have been lost to this ten-year-old.
Facebook doesn’t publicize data on exactly how often a user logs in, though you can bet that they’ve got that information. In lieu of that measurement, this app runs through the timestamps on every post in your feed until it reaches the earliest one, which it uses as the estimated date that you created your profile. Users who are extraordinarily active on the site may get an estimate that is considerably later than the actual date that they joined.