Plan a night of observing

The Night planner tab answers the questions you ask before going outside: when does it get dark, where is the Moon, and which planets are worth a look? All times are local times of the place in the side panel, for the date in Local date.

Sun and twilight

The first table lists the day from Astronomical dawn to Astronomical dusk:

• Sunrise and Sunset follow the convention of the U.S. Naval Observatory: the top edge of the Sun touches an ideal sea-level horizon, with standard refraction. Skyfold matched the Observatory's tables to the minute in its tests.
• Civil, nautical and astronomical twilight end when the Sun is 6°, 12° and 18° below the horizon. Only after astronomical dusk is the sky fully dark for faint objects.
• Morning golden hour ends and Evening golden hour begins use the common photographers' definition (Sun below 6°); the blue hour lies between civil dawn or dusk and a Sun 4° below the horizon.
• Solar noon shows the Sun's highest altitude in brackets.

Under the table you find the day length and how many hours of truly dark night are left. Near the poles the planner says so when the Sun does not rise or does not set.

Moon and planets

The second table gives Rise, Highest (the transit time with the altitude in brackets) and Set for the Moon and all seven planets, plus their Magnitude (lower is brighter: Venus is about −4, Saturn about +1, Neptune near +8 and needs binoculars).

When to look summarises the night: evening sky, morning sky, all night or not visible. A planet counts as visible when it stands more than 5° high in the dark and is at least 12° from the Sun (8° for the Moon).

The Moon's phase and lit fraction appear below the table. A bright Moon washes out faint stars, so the days around New Moon are best for deep-sky photos.

Coming up and the observation plan

Coming up lists the next Moon phases and every eclipse in the next three years that can be seen from your place. Press Add to plan next to an entry to copy it into Observation plan, with the place name as a note.

When the plan holds what you want, press Download calendar (.ics). Every event gets a reminder 30 minutes before it starts, and calendar apps show it in your own time zone. The same file is available under Export → Observation plan as calendar (.ics).

Use the trash icon next to a plan entry to remove it. The plan is saved with the project but is never included in share links.

Export the tables

Export → Night planner as CSV writes the Moon and planet rows and the Sun times for spreadsheets. To compare places, save each one with Save this place and switch between them with Quick place — the planner updates at once.

Next: chase an eclipse.