Sundial program This program creates charts showing the direction and length of a shadow cast by the top of a pole (gnomon) of a given height upon a rectangular area, typically a roof or a field. The shadow cast by a pole can be drawn on the diagram by connecting a line from the pole's location (0, 0) to the end of the shadow at the time of interest. Shading of a PV array, by a pole or object causing the shading, can be seen by drawing the location of the array on the diagram relative to the pole. By default, dates are spaced about 30 days apart from one solstice to the next. The width and length of the plotted area can be specified and there are a several options available to allow you to alter the chart's appearance. Resulting charts are displayed in your Web browser window, and they are formatted for printing. Two file formats are currently available: PDF (Adobe), and PNG, an international standard. Please note that some charts, especially those for Arctic or Antarctic latitudes and those where the gnomon height is very short in relation to the dimensions of the chart, may have labels crowded together or otherwise display unexpected properties. Be sure to experiment with various sizing and display options. Step 1—Specify location   Use these values:         Latitude (decimal degrees)         Longitude (decimal degrees)     [Important: south latitude and west longitude are given in negative degrees. Minutes and seconds must be converted to decimal degrees; e.g., 30 min. = 0.5 deg.]   Look up location with:         US 5-digit ZIP code Step 2—Specify time zone   Time zone UTC - 12h UTC - 11h UTC - 10h (HST) UTC - 9h30m UTC - 9h (AKST) UTC - 8h30m UTC - 8h (PST) UTC - 7h (MST) UTC - 6h (CST) UTC - 5h (EST) UTC - 4h (AST) UTC - 3h30m UTC - 3h UTC - 2h UTC - 1h UTC UTC + 1h UTC + 2h UTC + 3h UTC + 3h30m UTC + 4h UTC + 4h30m UTC + 5h UTC + 5h30m UTC + 6h UTC + 6h30m UTC + 7h UTC + 7h30m UTC + 8h UTC + 8h30m UTC + 8h45m UTC + 9h UTC + 9h30m UTC + 10h UTC + 10h30m UTC + 11h UTC + 11h30m UTC + 12h UTC + 13h UTC + 14h Step 3—Choose data to be plotted   Plot dates 30 or 31 days apart, between solstices, December through June   Plot dates 30 or 31 days apart, between solstices, June through December   Plot dates having average solar radiation for December through June   Plot dates having average solar radiation for June through December   Plot only this date (YYYY-MM-DD):   Plot hours in local solar time   Plot hours in local standard time   Show hours in international style   Show hours in am/pm style   Do not label hour curves Step 4—Specify sun dial dimensions.         Length         Width above gnomon base         Width below gnomon base         Gnomon height         Dimension units Step 5—Set chart format parameters   Color date curves Black White Red Green Blue Cyan Yellow Orange Magenta Brown   Set style of date curves to Solid Dots Dashes   Make date curves 1 2 3 pixels wide   Color hour curves Black White Red Green Blue Cyan Yellow Orange Magenta Brown   Set style of hour curves to Solid Dots Dashes   Make hour curves 1 2 3 pixels wide   Color background White Light blue Light gray Black Red Green Blue Cyan Yellow Orange Magenta   Color border area Light blue Light gray White Black Red Green Blue Cyan Yellow Orange Magenta   Color axes Black White Red Green Blue Cyan Yellow Orange Magenta Brown   Make axes 1 2 3 pixels wide   Color grid Light gray Light blue Black White Red Green Blue Cyan Yellow Orange Magenta Brown   Make grid 1 2 3 pixels wide   Color labels Black White Red Green Blue Cyan Yellow Orange Magenta Brown   Enter text to display on the chart. Parameters such as latitude will be shown automatically.   Optional text (e.g., location name)   Additional text Step 6—Choose file format for chart   PDF (Portable Data Format). We recommend this format, provided you have Adobe Acrobat Reader installed on your computer. PDF files can be easily resized to fit any printer page size.   PNG (Portable Network Graphics). This format may be useful if you want to save the image from your Web browser in order to import it into another document that will be published, projected, etc. Note that some Web browsers may be unable to easily resize an image in this format for direct printing. Usually, a landscape page with no headers or footers, magnified about 122% can be printed with good results. Step 7—Click the 'Create chart' button © 2022, UO Solar Radiation Monitoring Laboratory. Last revised: March 6, 2022. Top of page Site map Software tools Home page Search About sun charts Sponsors Contact us Home page URL: solardata.uoregon.edu