Rising Sun and Moon Calculator

Rising Sun and Moon Calculator

Positive for North, Negative for South

Positive for East, Negative for West

Results Summary

Approx. Sunrise: —

Approx. Sunset: —

Daylight Duration: —

Moon Phase: —

Moon Age: —

*Calculations are approximate based on atmospheric refraction and standard orbital parameters. Local topography and time zones may vary results.

function calculateCelestialData() { var lat = parseFloat(document.getElementById('latitude').value); var lon = parseFloat(document.getElementById('longitude').value); var dateVal = document.getElementById('obsDate').value; if (isNaN(lat) || isNaN(lon) || !dateVal) { alert("Please provide valid coordinates and a date."); return; } var d = new Date(dateVal); var dayOfYear = Math.floor((d – new Date(d.getFullYear(), 0, 0)) / (1000 * 60 * 60 * 24)); // Solar Calculations (Simplified) var declination = 23.45 * Math.sin((360 / 365) * (dayOfYear – 81) * (Math.PI / 180)); var latRad = lat * (Math.PI / 180); var decRad = declination * (Math.PI / 180); var cosHourAngle = (Math.cos(90.833 * Math.PI / 180) – (Math.sin(latRad) * Math.sin(decRad))) / (Math.cos(latRad) * Math.cos(decRad)); var resultsArea = document.getElementById('resultsArea'); resultsArea.style.display = 'block'; if (cosHourAngle > 1) { document.getElementById('sunriseTime').innerText = "Polar Night"; document.getElementById('sunsetTime').innerText = "Polar Night"; document.getElementById('dayLength').innerText = "0 hours"; } else if (cosHourAngle 9) r -= 19; r = ((r * 11) % 30) + month + day; if (month < 3) r += 2; r -= ((year < 2000) ? 4 : 8.3); r = Math.floor(r + 0.5) % 30; if (r < 0) r += 30; var phase = ""; if (r < 1.84) phase = "New Moon"; else if (r < 5.53) phase = "Waxing Crescent"; else if (r < 9.22) phase = "First Quarter"; else if (r < 12.91) phase = "Waxing Gibbous"; else if (r < 16.61) phase = "Full Moon"; else if (r < 20.30) phase = "Waning Gibbous"; else if (r < 23.99) phase = "Last Quarter"; else if (r = 12 ? 'PM' : 'AM'; h = h % 12; h = h ? h : 12; return h + ":" + (m < 10 ? '0' + m : m) + " " + ampm; }

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Understanding Sun and Moon Cycles

The movement of the sun and moon governs life on Earth, from the tides in our oceans to the circadian rhythms of our bodies. A Rising Sun and Moon Calculator helps astronomers, photographers, and outdoor enthusiasts determine the exact moments of celestial transitions based on geographical coordinates.

Solar Mechanics: Why Sunrise Changes

The Earth's axial tilt of 23.5 degrees is the primary reason why sunrise and sunset times shift throughout the year. During the summer solstice, the hemisphere tilted toward the sun experiences the longest day of the year. Conversely, the winter solstice brings the shortest day. Our calculator uses your Latitude and Longitude to solve the solar declination equation, providing an estimate of when the sun will cross the horizon.

The Lunar Cycle and Phases

Unlike the sun, the moon's cycle is roughly 29.5 days long. This is known as a synodic month. The "Moon Age" refers to the number of days since the last New Moon.

• New Moon: The moon is between the Earth and Sun (invisible).
• Waxing: The illuminated portion is growing.
• Full Moon: The Earth is between the Moon and Sun.
• Waning: The illuminated portion is shrinking.

Calculation Example

If you are standing in New York City (Lat: 40.71, Lon: -74.00) on June 21st:

• Declination: ~+23.4° (Max tilt toward Sun)
• Day Length: Approximately 15 hours and 5 minutes.
• Sunrise: Typically around 5:25 AM local time.

By inputting your specific coordinates, this tool accounts for the curvature of the Earth to give you the most accurate celestial window for your location.