Want to know the exact time of sunrise in 2000? Or Carl Lehrburger's account of an equinox site with a noon hour sundagger formed by fallen rock? Then this site is for you. Uncommon information is provided such as "Old Celtic calendars observed Cross Quarters, approximately midway between each pair of adjacent Equinox and Solstice days. Unlike modern calendars that define the start of a season on a Solstice or Equinox, the Celts perceived Solstices and Equinoxes as events occurring mid-season, with the seasons actually beginning and ending on the Cross Quarters." Interesting bibliography on ancient American petroglyphs and alignments.

Here is Dr. Daniel Roth’s simple Azimut und Elevation der Sonne calculator based on equations from Pfeger’s Astronomy with the Personal Computer. Simple to use. There are other programs as well, including a calendar for any year, and the date of Easter.

This program by Steven Pugh is an apple to show which parts of the globe are in daylight and which are in darkness. The position of the sun (projected on to the Earth) is shown as a yellow circle. Various locations around the world can be selected, and the date and time can be changed. For the currently selected location and the current date and time, information such as the number of daylight hours and sunrise/sunset times are shown in a panel on the right-hand side.  A plane or topographic map can be selected.

Have you ever wondered what the division between day and night might really look like from space?  The Earth and Moon visualizer does exactly that.  Created by John Walker, co-founder of Autodesk, a variety of globe and topographic map views are available at the click of a mouse.  Clouds?  Today's weather?  City lights?  It's all there at your command.  And click on "Details" explains how this all came about and the resources used to assemble these remarkable views.

James River Sundials may not be building sundials that you can pick up and take home, but artisan and dialist Bill Horst provides some simple and effective software for drawing the classic gnomonic sundial using a single vertical stick and a modern bifilar sundial using two horizontal wires that create crossing shadows.  You can also find all the equations to calculate the layout of the clasic sundial using vectors.