Find your window to the stars

Dark Sky & Moonlight Planner

Find moon-free darkness for stargazing. Choose an evening and place to explore the night from noon to noon.

Preset places use the selected evening's time zone. For custom coordinates, enter the local UTC offset. One offset applies to the whole night; on clock-change nights, times after the change need adjusting. Coordinates are used for this calculation and are not saved by ChronoWaves.

Preparing your night…

Make the most of the night

What makes a dark-sky window?

Beyond twilight

Astronomical darkness begins when the Sun is at least 18° below the horizon. Some summer nights and polar locations never reach it.

The Moon below the horizon

We highlight darkness with the Moon below the apparent horizon. The Moon-up band indicates possible moonlight, not a brightness forecast; a thin crescent and a full Moon have very different effects.

Look at local conditions

Cloud, haze, artificial light and obstructions still affect the view. Give your eyes time to adjust and choose a place away from bright lights.

Times are estimates from ChronoWaves' approximate Sun and Moon positions, sampled once per minute with an approximate lunar parallax correction. A flat horizon is assumed. Phase and illumination are shown at local midnight. Windows touching noon are clipped to the planning period.

Twilight definition: U.S. Naval Observatory.

Moonrise & moonsetMoon path tonightMoon phase calendar