All tools
Daylight Simulator
HK defaultSeason & latitude
13.4 h
daylight today
Synced Earth–Sun model
Before you start
Day length depends on your latitude and the season. This tool links the numbers to Earth's orbit.
Key idea
When the northern hemisphere tilts toward the Sun, days lengthen. At the equator, day and night stay roughly equal year-round.
What you see
- Daylight hours readout
- Synced Earth–Sun orbit diagram
- Daylight bar showing hours of light
Try this
- Set latitude to Hong Kong and slide through the year
- Compare HK with a city at 45°N on the same day
- Find the day with exactly 12 hours of daylight at the equator
Why it matters in Hong Kong
Hong Kong sees about 10.5 h of daylight in winter and 13.5 h in summer.
Common mistakes
- Forgetting atmospheric refraction makes the Sun visible slightly longer than geometry predicts
Glossary
- Declination
- Sun's celestial latitude, driving seasonal day length.