Cairn counts down to the days you're waiting for, and counts up from the days you don't want to forget. Give it a date. It answers in days — 124 days to go, or 1,024 days since. Everything else gets out of the way. COUNTDOWN AND COUNT-UP, ONE MODEL • Days to go for anything ahead: a holiday, a trip, an exam, a due date • Days since anything behind: an anniversary, a baby's birth, the day you quit • Turn on minute precision when the hour matters — "3 days 4 hours", with seconds only in the…