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Caluclating the time of sunrise and sunset

Produced by Takehiko Hoshi (Kindai Univ.)
Reference: Kou Nagasawa(2000), Calclation of sunrise and sunset, Chijin-Shoin, Japan.

The length in the daytime and nighttime by the rotation of the earth greatly affects plant growth and human life. In this page, sunrise and sunset in optional date of the whole world are calculated. It can be used, even if it is not connected with the internet, if this page is copied to your personal computer, since it is written in JavaScript. In the program, the computation error of plus-minus 1 minute maybe occurs, because the calculation in every 1 minute is performed.

Location

If you don't find the place name, please input longitude and latitude below.

Map Interface (If you click the map, location data will be put into below forms.)

(Caution): If outside of Japan area or less than 0 m of elevation, The altitude value should be 0 m.
The value of Time zone offset is approximated by the longitude value.
Latitude degree Longitude degree Altitude meter
(the north latitude is in plus value, the south latitude is in minus value,
the east longitude is in plus value, and the west longitude is in minus.)

Date

Year Month Day
Time zone offset to GMT Hours

Results

Explanation of terms

Astronomical twilight:: The time zone in which the effect of the sun remains in visual performance of heavenly body.
Voyage twilight:: The time zone in which the scenery in the circumference is dimly seen.
Citizen twilight:: The time zone which can be active in the outside, even if the sun is hidden.
Sunrise:: The case in which the upper end in the sun is seen from horizontal line.
Sunset:: The case in which the upper end in the sun perfectly sank in horizontal line.
Meridian:: The case in which the sun is the highest and in which it is located in the due south(north).
Altitude:: The angle which made the horizontal to be the 0 degrees.
Direction:: The angle which made the north ( the south ) to be the 0 degrees.