Sky Path
A live view of the sun and moon's path across the sky for your selected date and location -- a bird's-eye diagram of where each rises, how high it climbs, and where it sets, rather than just a list of times.
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Sun
Moon
Page help ⌄
How to read this: This is a bird's-eye view of the sky, looking straight up. The center point is directly overhead (zenith); the outer edge is the horizon. The compass letters show which direction to face. Hover (or touch and drag) anywhere in the circle to see the exact time, elevation, and compass direction for both the sun and moon at that point along the path. Where a curve is drawn dashed and dimmer, that portion belongs to the previous or next calendar day rather than the one selected above -- this happens most often with the moon, whose rise and set times drift by about 50 minutes each day, so it frequently rises one day and doesn't set until sometime the next.
Key Definitions
- Azimuth
- Compass direction measured clockwise from true north (0°/N through 90°/E, 180°/S, and 270°/W back to N) -- which way to face to look at an object.
- Elevation (altitude)
- How high an object sits above the horizon, in degrees. 0° is right at the horizon, 90° is straight overhead at the zenith.
- Solar noon
- The moment the sun reaches its highest elevation for the day, crossing due south (or due north, south of the equator). Despite the name, it's rarely at 12:00 clock time -- time zones and daylight saving shift it, sometimes by an hour or more.
- Zenith
- The point directly overhead, 90° above the horizon -- the center of this diagram.
How this works: Sun and moon positions are calculated for your exact location and date using reduced-precision solar and lunar position theory -- algorithms that trade a small amount of accuracy (well under an arcminute of typical error for the sun, and larger but still small for the moon) for speed, so the whole sky path can update instantly as you drag the time slider or change dates. This is the same underlying math used across the Sun, Moon, and Almanac tabs, so the times and positions stay consistent everywhere in the app.
Sun
Sunrise, sunset, solar noon, day length, and the next solar eclipse for your selected date and location, each as a card you can tap for a deeper explanation and a chart of how it changes over time.
Page help ⌄
How to use this page: click any card for a short explanation of what it means and why it changes. The small circle in the bottom-right corner of most cards graphs that value below -- click up to two to compare them, gold for the first and blue for the second; click a selected one again to remove it. Use the Week, Month, or Year buttons above the chart to change how much time it covers, and hover anywhere on the chart to see the exact value for that day. Your selections are remembered the next time you visit.
Moon
Moon phase, moonrise, moonset, illumination, distance, and the next lunar eclipse for your selected date and location, each as a card you can tap for a deeper explanation and a chart of how it changes over time.
Page help ⌄
How to use this page: click any card for a short explanation of what it means and why it changes. The small circle in the bottom-right corner of most cards graphs that value below -- click up to two to compare them, gold for the first and blue for the second; click a selected one again to remove it. Use the Week, Month, or Year buttons above the chart to change how much time it covers, and hover anywhere on the chart to see the exact value for that day. Your selections are remembered the next time you visit.
Key Definitions
- Full moon
- Earth sits between the sun and moon, so the moon's entire near side is lit -- the brightest phase, rising around sunset and setting around sunrise.
- Illumination
- The percentage of the moon's visible disk that's lit by the sun at a given moment -- 0% at new moon, 100% at full moon.
- Lunar eclipse
- The moon passes through Earth's shadow, which can only happen at full moon. Visible from anywhere the moon is above the horizon at the time -- no narrow viewing path required, unlike a solar eclipse.
- New moon
- The moon sits between Earth and the sun, its lit side facing away from us -- effectively invisible in the sky. The start of the lunar cycle.
- Waxing / waning
- Waxing means the illuminated portion is growing (new moon toward full); waning means it's shrinking (full moon back toward new).
Almanac
A day-by-day table of sun and moon data for your selected date range and location -- sunrise, sunset, moonrise, moonset, moon phase, and more, laid out for scanning across a week, month, or year at a glance.
Page help ⌄
How to read this table: click any column header to sort by it, and click again to reverse the order. The single best value in a highlighted column — like the earliest sunrise or the closest moon — is marked in gold for the days currently shown. Scroll right for more columns; the date stays pinned on the left.
Solar Eclipses
The shadow path of every total, annular, and hybrid solar eclipse through 2055, plotted on a map -- pick an eclipse below to see exactly where it crosses the Earth, and whether your own location falls on the path.
Page help ⌄
How to use this page: Prev/Next or the dropdown picks which eclipse to show -- there's no date to navigate to, since eclipses only happen on their own specific days. The cards above summarize that eclipse's own numbers; the "Your location" card checks your saved location against the actual shadow path shown on the map below.
How to read the map: the shaded band is the path of totality (for a total eclipse) or annularity (for an annular one) -- only inside it does the Moon fully cover the Sun. A hybrid eclipse shifts between the two along its own path. The gold line down the middle is the central line, where the eclipse lasts longest; the gold dot is the point of greatest eclipse, where it peaks. Hover the map for the exact coordinates and whether that point sits on the path.
How to read the map: the shaded band is the path of totality (for a total eclipse) or annularity (for an annular one) -- only inside it does the Moon fully cover the Sun. A hybrid eclipse shifts between the two along its own path. The gold line down the middle is the central line, where the eclipse lasts longest; the gold dot is the point of greatest eclipse, where it peaks. Hover the map for the exact coordinates and whether that point sits on the path.
Key Definitions
- Umbra / antumbra
- The umbra is the Moon's full shadow, inside which the Sun is completely covered (a total eclipse). When the Moon is too far from Earth to fully cover the Sun, its shadow narrows to an antumbra instead, inside which a ring of sunlight remains visible around the Moon (an annular eclipse). Both are drawn the same way here, as the shaded path.
- Hybrid eclipse
- A rare eclipse that's total along part of its path and annular along the rest, because Earth's curved surface brings some points slightly closer to the Moon's shadow than others.
- Central line
- The line through the middle of the shadow path where the eclipse lasts longest at any given point along the path.
- Greatest eclipse
- The single point and moment where the Moon's shadow axis passes closest to Earth's center -- generally close to, but not always exactly on, the point of longest duration.
- Magnitude
- The fraction of the Sun's diameter covered by the Moon at greatest eclipse, as seen from the central line. Below 1.0 the Moon doesn't fully cover the Sun (annular); 1.0 or above it does (total).
- Gamma
- How close the Moon's shadow axis passes to Earth's center, in Earth radii -- 0 is dead center, and the closer to +-1 it gets, the more the path is squeezed toward a pole (or misses Earth entirely beyond that).
- Saros series
- A family of eclipses that repeat roughly every 18 years 11 days with similar geometry, as the Sun, Moon, and Earth return to nearly the same relative positions. Eclipses in the same series share a number.