Rise and set times for the sun and moon

By far the most common enquiry we have is for the time of sunrise and sunset on a particular day at a particular location. These links point to the sites that we use to obtain this information. We include a brief explanation of how to obtain sunrise/set information from the selected links. These links will also be useful for moon phases, moonrise/set times and other information regarding the sun and moon

Rise and Set Times

All you need for calculating rise and set times.
* Sun or Moon Rise/Set Tables for One Year
Provided by the US Naval Observatory, this is the easiest way to get rise or set times off the web. A guide on how to use this service is given below.
* The Astrodienst Atlas Database
Actually part of an astrology site, this page enables you to search for the latitudes and longitudes for over quarter of a million towns worldwide. A particularly useful resource.
* The World Clock Timezone Database
Gives you local time in many of the world's largest cities. Contains useful information on daylight saving time conventions, timezones and more.

Moon Phases

* Moon Phase Calendar
Shows you what the moon looks like on every day of every month.
* Fraction of the Moon illuminated
Calculate the illuminated fraction of the moon for the years 1700 - 2100
* Islamic Moon-Sighting Calculations
A page maintained by and for members of the Islamic community. Contains detail of upcoming events in the Islamic calendar.

Other Sun and Moon Data

* USNO Astronomical Applications
The best site on the web for obtaining ephemerides of the Sun and moon, plus much more.
An excellent application from USNO for calculating the positions of the sun, moon, planets, and bright stars in the sky from any location (select "Apparent coordinates: topocentric Alt & Az, wrt local horizon").
* Variation in Time of Sunrise
An essay detailing the mathematical calculation of sunrise and sunset times. For the keen.
* Times of the Earth's Perihelion and Aphelion 1992-2005
Includes date and times of the Equinoxes and Solstices. Another part of the US Naval Observatory's marvellous data service whose front end is here...

How to calculate rise and set times

Since rise and set times for the sun and moon are such a popular request for us, it is worth mentioning a few tips on the subject:

* Obtain the Latitude and longitude
The times or rise and set of astronomical objects depend on your location. From a good atlas, or something like the the Astrodienst Atlas Database, make a note of the latitude and longitude of the town or city nearest to you. You don't have to be too accurate - the difference in times between two places even 20 or so miles apart is never more than a couple of minutes. Latitude and longitude are normally quoted in degrees and minutes (e.g N56 25 means North 56 degrees and 25 minutes - NOT 56 and a quarter degrees). Make sure you know what you have and what you need. The USNO software (Mica) that we recommend above, requires its input in degrees and minutes.
* Work out the timezone
Rise and set times are normally given in GMT or Universal time (the same thing). Be aware that the place you have calculated the times for may sit a long way to the east or west of the Greenwich Meridian. If so then you will need to add (if to the west) or subtract (if to the east) the appropriate time difference. The World Clock Timezone Database tells you the offsets from Greenwich for a number of different cities. Again, a good atlas should contain the same information.
* Don't forget Summer Time
During summer months many countries observe Daylight Saving Time. The DST offset is usually +1 hour from GMT. If your rise and set times are GMT make sure you add one hour to get the correct "local" times. The The World Clock Timezone Database has the dates when DST begins and ends for major cities worldwide. The Royal Greenwich Observatory prodives a list ofcountries that do not observe day-light savings.
* Lighting up time
Sunrise and sunset times are NOT the same as lighting up times. Street lamps in the UK are generally come on about half an hour after sunset and turn off about half an hour prior to sunrise.
* Hours of Darkness
When the sun goes down and when it actually gets dark are not always the same thing - particularly for northerly or southerly latitudes. Civil twilight is, as a rule of thumb, the time when it becomes too dark to perform detailed operations outdoors without artificial lighting. The brightest stars and planets are visible at this time. Civil, nautical and astronomical twilight times can be calculated using the USNO software.

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