How to read sunrise and sunset times

Pick a spot to see that day's sunrise, sunset and twilight times. Values come from the Korea Astronomy and Space Science Institute or a standard astronomical formula.

What this page shows

Pick a spot and you get sunrise, sunset, twilight and day length for all 365 days of the year. Today is shown first, and you can also jump to January 1 or any other date.

Times are Korea Standard Time (KST). We do not print seconds, and the calculation error is roughly that size, so we do not show a precision we do not have.

Reading sunrise and twilight

  • Sunrise is when the sun's upper edge reaches the horizon, corrected for how the atmosphere bends light.
  • Civil twilight begin is when the sky starts to lighten before sunrise. Arrive by this time if you want to watch the whole process.
  • Solar noon is when the sun is highest that day, not exactly halfway between sunrise and sunset.
  • Day length runs from sunrise to sunset and changes with the season.

Where the numbers come from

The primary source is the Korea Astronomy and Space Science Institute's rise/set data (data.go.kr). Days fetched from it are marked 'KASI' on the spot page.

Days we could not fetch are calculated with the NOAA Solar Calculator formula, a published method for computing the sun's position directly. Those days are marked 'calculated', with error typically under a minute.

Planning a January 1 sunrise

Every late December, more people plan a trip to watch the first sunrise of the year. Crowds on January 1 often mean arriving well before the civil-twilight-begins time.

Each spot page lists its address and a map link. If you need a place to stay, that is listed below the spot's times.

What this app does not do

It does not forecast weather. Clouds can hide the sun even at the calculated sunrise time; check the weather service separately.

It does not cover parking or traffic control at the site. Check each local government's own notice for that.

Common snags

My spot is not listed. Only twelve spots exist so far. We only add spots with an official source for the name and address.

The table says 'calculated'. We have not fetched the institute's original data for that day yet. Error is typically under a minute.

There are no seconds in the time. The calculation error is about that size, so we do not print a precision we do not have.