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Big Dipper Clock

HK default

Big Dipper seasonal clock

In the northern hemisphere, the Big Dipper's orientation changes through the night and through the year. Ancient observers used it as a clock and calendar. Hong Kong uses standard time year-round — no daylight saving.

Northern sky — Hong Kong

PolarisFacing north — stars rotate counterclockwise through the night

Pointer stars of the Dipper aim toward Polaris, about 22.4° above the northern horizon in HK.

Before you start

Before clocks and calendars, northern cultures used the Big Dipper's orientation to tell time at night and season of year.

Key idea

The Big Dipper circles Polaris counterclockwise once per day. Its orientation also shifts gradually through the year as Earth orbits the Sun.

What you see

  • Big Dipper asterism rotating around Polaris
  • Month and hour controls (Hong Kong local time, no DST)

Try this

  1. Set month to March and hour to 10 PM — note the Dipper's orientation
  2. Change only the hour — watch daily rotation
  3. Change only the month — watch seasonal shift

Why it matters in Hong Kong

Hong Kong does not use daylight saving time, so local clock time matches this simulator directly.

Common mistakes

  • Expecting the Dipper to be visible from southern hemisphere locations
  • Forgetting that Polaris is not exactly at the north celestial pole

Glossary

Circumpolar
Stars that never set — always above the horizon.
Polaris
The North Star, very close to the north celestial pole.

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