Sunrise and Sunset Times by City

Sunrise and Sunset Time Calculator: Core Features and Principles

Planning an outdoor activity but don't know the exact sunrise time? Based on the NOAA Solar Calculator astronomical algorithm, this tool accurately calculates the sunrise, sunset, solar noon, and daylight hours for a specific date by entering a city name or latitude/longitude coordinates. Daylight hours refer to the actual daytime between sunrise and sunset, including atmospheric refraction correction (standard value 0.833°), ensuring a calculation error of ≤±60 seconds.

Why Choose Our Sunrise and Sunset Time Calculator?

• Supports 30 years of historical data and 10 years of future predictions, covering the complete time span from 1994 to 2034.
• Utilizes the VSOP87 planetary theory model with automatic longitude time difference correction, making it more accurate than standard calculators.
• Visual daylight hours bar chart for intuitively comparing day and night variations across different dates.

How to Use the Tool

1. Enter the target city (e.g., "Beijing") or decimal latitude and longitude (e.g., 39.9042, 116.4074) in the input box.
2. Select the query date (defaults to today, supports quick switching via the date picker).
3. Click the calculate button to get the complete astronomical timetable including the local time zone.

Frequently Asked Questions (FAQ)

• Q: Why do cities at the same latitude have different sunrise times?
  Short answer: It is affected by longitude time differences. Detailed explanation: Even if the latitude is the same, longitude differences will cause a deviation between local mean time and standard time zone time. This tool has a built-in longitude time difference correction algorithm.
• Q: How are results displayed for polar regions? For polar day and polar night regions with a latitude > 66.5°, the status will be clearly marked as "Midnight Sun" (all-day daylight) or "Polar Night" (all-day darkness), along with the time range this phenomenon lasts.

Important Notes

When using decimal latitude and longitude, the latitude range is -90 to +90, and the longitude range is -180 to +180. It is recommended to keep 4 decimal places. Please use standard geographical names for cities (e.g., "Guangzhou") and avoid abbreviations to prevent matching errors. The results default to your browser's time zone; if you need a fixed time zone, please set it before calculating.

Technical Notes & Tips

For photography enthusiasts, we recommend paying special attention to the "Civil Dawn" and "Civil Dusk" times (when the sun is 6° below the horizon), which are the best times for capturing the golden hour. Typical input/output example: Input "Shanghai 2024-12-21", output sunrise 06:50, sunset 16:59, daylight 10 hours 9 minutes, intuitively demonstrating the short daylight characteristics of the winter solstice.