At what time does the sun rise and set? How long is twilight? An ephemeris is a daily table of such times. The charts below combine ephemerides for the sun and the moon. You can see which days of the year will have a moon at night, and which will have the moon at daytime. Click for a larger picture.
The year runs from left to right. Each day goes from bottom to top. The broad sweep of light and dark show the sun. See how Vostock Base in the Antarctic has a whole week at the start of May where there is a sort of twlight, but the sun never even makes it above the horizon. The narrower bands show when during the day the moon is above the horizon. This is not the same as phases of the moon; they are shown with small dots.
The data all comes from an online ephemeris calculator provided by the Astronomical Applications department of the US Naval Observatory. Many thanks to them! The buttons below will fetch data from the Observatory's and plots a diagram, like those above. But please don't overload the Observatory's online calculator.
| International | North America | |
Notes: After you click "Plot", it will take up to a minute to fetch the data. For US cities, spell them out, as in "East Orange", "Fort Lauderdale", "Mount Vernon". Except for "St." as in "St. Louis".