Most time zones are whole hours — not all

A handful of zones sit on the half-hour or even quarter-hour: India (+5:30), Nepal (+5:45), parts of Australia (+9:30, +8:45).

Why it works

These offsets follow old longitude/political boundaries rather than clean 15° meridian slices — always double-check before assuming a round-hour gap.

Do it exactly

Estimate with the rule, then check it against the calculator that models it properly.

Open Time Zone Converter →

More in Environmental

• Lightning distanceCount the seconds from flash to thunder, divide by 3 for kilometres (by 5 for miles).
• Air cools as you climbTemperature drops about 6.5 °C for every 1,000 m of altitude.
• Pressure halves every ~5.5 kmAtmospheric pressure falls by half roughly every 5,500 m you climb.
• Ten metres of water = one atmosphereEvery 10 m of seawater adds about 1 atmosphere of pressure.

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