Sun below −18° · next 30 nights

True darkness at Queenstown

Astronomical darkness starts only when the Sun is 18° below the horizon. These bars are calculated for the coordinates, so high-latitude nights correctly show no true darkness when twilight never ends.

Longest night6.0 h3 Nov

Nights reaching −18°30 / 30Astronomical darkness occurs

Longest window22:40–04:40Moonlight is shown separately in the planner.

Solar geometry, not a clock rule

Hours of astronomical darkness

3 Nov6.0 h33% moon

4 Nov6.0 h23% moon

5 Nov6.0 h14% moon

6 Nov5.3 h8% moon

7 Nov5.3 h3% moon

8 Nov5.3 h1% moon

9 Nov5.3 h0% moon

10 Nov5.3 h2% moon

11 Nov5.3 h5% moon

12 Nov5.3 h10% moon

13 Nov5.3 h16% moon

14 Nov5.3 h23% moon

15 Nov4.7 h32% moon

16 Nov4.7 h41% moon

17 Nov4.7 h51% moon

18 Nov4.7 h61% moon

19 Nov4.7 h70% moon

20 Nov4.7 h79% moon

21 Nov4.7 h87% moon

22 Nov4.7 h94% moon

23 Nov4.7 h98% moon

24 Nov4.3 h100% moon

25 Nov4.3 h99% moon

26 Nov4.0 h95% moon

27 Nov4.0 h89% moon

28 Nov4.0 h81% moon

29 Nov4.0 h71% moon

30 Nov4.0 h60% moon

1 Dec4.0 h49% moon

2 Dec4.0 h38% moon

6.0 hours

Use this as the outer boundary for faint-object work. Moon altitude, cloud and transparency will narrow the practical window. Add the Moon →

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Find the longest uninterrupted dark windows.

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Milky Way

See when the galactic core clears the horizon after dark.

−18°

Astronomical darkness

Track true darkness, including polar twilight.