KDay Turns Your Life Into a Calendar of 1,000-Day Birthdays

Why it surfaced

It takes an overlooked number—your age in days—and gives it a wonderfully tangible consequence: cake on an otherwise ordinary Tuesday. The calculator is free, works in 40 languages, and says that dates stay on the phone with no account required.

KDay calculates how many days you have been alive and finds the next milestone every 1,000 days, with reminders and celebration ideas for iPhone.