Astronomy Tools
Solar and lunar planning
Moon & Darkness Planner
Compare Moon phase, moonrise and moonset, twilight and truly dark observing time for locations across South Africa.
Observing location
Choose a town, use your position, or enter coordinates.
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Planning period
Start tonight or choose a future date up to one year ahead.
Unable to calculate this plan
Please check the selected location and date.
Best dark-sky opportunity
Cape Town darkness outlook
Calculating the best moonless observing period…
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Calculating
Darkness outlook
Select a night to see its Moon, twilight and darkness timeline.
Selected night
Moon and darkness details for the selected date.
Moon phase
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-- illuminatedThe phase is calculated near the middle of astronomical darkness.
Best moonless window
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Calculating when the Moon is below the horizon during astronomical darkness.
Sunset
Night timeline
Sunrise
Sky
Moon
Civil twilight
Nautical twilight
Astronomical twilight
Astronomical darkness
Moon above horizon
How to use the planner
Darkness calculations are independent of weather and local light pollution.
Astronomical darkness
Starts when the Sun is 18° below the horizon and ends at astronomical dawn.
Moonless darkness
The portion of astronomical night when the Moon is below your local horizon.
Darkness score
Rewards long moonless periods and reduces the score when a bright Moon is above the horizon.
Local horizons
Buildings, mountains and atmospheric refraction can shift observed rise and set times by several minutes.
Solar and lunar calculations run locally in your browser using a bundled, BSD-licensed implementation based on SunCalc. Times use South African Standard Time (UTC+2). The planner does not send your coordinates to an external service.