The app
Just Start Time
The 9 a.m. call you took at 9 p.m.
Compare time zones without doing the math in your head.
What it does
Line up time zones side by side and see what time it is for everyone at once, so you can pick a slot that works without counting on your fingers.
Why it matters
Everyone gets this wrong eventually, and it's never a small mistake — it's a missed call with a client, or a family member woken at 3 a.m. The mental arithmetic is where it goes wrong.