Have you ever wondered exactly when you turn 1 billion seconds old? Or what day you hit 10,000 days on Earth? Bonus Birthdays is a calendar app that finds the weird, wonderful, and mathematically sound milestones hiding between your real birthdays. It’s perfect for finding your own next party, or better yet—entering a friend’s date so you can completely surprise them with a congratulatory text on their 400th month! Because waiting 365 days for cake is just too long 🍰