Guides

The why behind the clock and the sky

Our tools give you the numbers. These plain-English guides explain where the numbers come from — no jargon, no fluff.

🌍 How time zones work

UTC, offsets, half-hour zones, and the volunteer-run database that keeps every phone on Earth honest. Why railroads invented the whole system, and why China runs on a single clock.

🕐 Daylight saving time, explained

Why we spring forward and fall back, which countries refuse to, what the switch does to your body, and practical tips for surviving it twice a year.

🌙 Moon phases without the jargon

Why the Moon changes shape, the one-second trick to tell waxing from waning, what supermoons and blue moons really are, and the best nights for stargazing.

⛅ How weather forecasts are made

Balloons, satellites, supercomputers, and the butterfly effect — plus what "70% chance of rain" actually means and how far ahead you can trust a forecast.

✈️ Jet lag: why it happens & how to beat it

Your body clock, why flying east hurts more than west, and the light-timing tricks that genuinely speed up recovery.

🌇 Golden hour & blue hour

Why low sun turns the light warm, how long the magic lasts at your latitude, and how to time photos, walks and proposals to it.

Why we write these

Time & Sky started as a set of fast, free tools — a world clock, a time zone converter, a weather forecast, and friends. But the questions behind the tools are genuinely interesting: why the world argues about clock time, why the Moon waxes and wanes, why a forecast is trustworthy on Tuesday and shaky by Sunday. These guides are our answers, written to be read by anyone. More are on the way.