Starry Night Pro FAQ - Time & Date

Starry Night Pro doesn’t display the correct time when I start up. How do I fix this?

Starry Night Pro reads the time from your computer’s Control Panel. Make sure it is set correctly there.

The correct time is shown when I start Starry Night Pro, but the sun rises and sets at the wrong time. How do I fix this?

Most likely you have entered the wrong time zone for your home location. Select "Go | Set Home Location" to see what the time zone is set at. Time zones are in relation to London, England. People on Eastern Time are 5 hours behind London time, so they should put "-5h" for their time zone. Those on Central Time would enter "-6h" and so on. Visit the World Time Zone Map if you do not know the time zone of your home location.

Do the sunrise/sunset times account for the refraction of light due to the earth's atmosphere?

Yes. The bending of light due to the Earth’s atmosphere is accounted for by simply lowering the horizon about 1/2 degree. This gives the correct rise and set times for the sun and moon but doesn’t affect the relative positions of the stars.

How does Daylight Savings Time work in Starry Night?

When you start up Starry Night, the program checks your computer's date/time settings to find out if Daylight Savings Time is in effect for the current date, and if so, automatically adjusts the sky to account for this. If Daylight Savings Time is "on" in Starry Night, the little icon of the sun immediately to the right of the time in the Time Palette will be coloured yellow. Click on this icon to turn off Daylight Savings Time (if Daylight Savings Time is already off, clicking on the icon will turn it on). Note that Starry Night only checks to see if Daylight Savings Time is in effect when you open the program. This means that you may have to turn on or off Daylight Savings Time if you change the date from within the program. For example, let's say you open the program in June. Starry Night checks with the operating system to determine that Daylight Savings Time is in effect, so the icon of the sun in the Time Palette is lit up. However, you are interested in viewing a solar eclipse in December, so you change the date in the Time Palette to sometime in December. Starry Night will not automatically turn Daylight Savings Time off. You need to click on the icon of the sun to manually turn Daylight Savings Time off.

Can I get Starry Night to show the time using the 24-hour clock?

Yes. On Windows, click the "Start" button on your desktop and choose Settings->Control Panel->Regional Options. Click the "Time" tab, and switch the time format to something other than the current setting. Then close and reopen this window and switch to the 24 hour clock. After restarting Starry Night it should be using the new time format. On the Macintosh you can change to the 24 hour clock from the Date and Time control panel. An earlier version of Starry Night did not allow users to use the 24-hour clock. If you still do not get the 24-hour clock in Starry Night Pro after following these instructions, you probably need to download the Starry Night Pro update.

Can I get Starry Night to show dates in the European format?

Yes. On Windows Starry Night looks to the Windows registry to determine the order in which to show dates. If it can't find a registry entry for regional date settings then it defaults to the US month, day, year. Unfortunately UK Windows does not automatically place the date format in the registry where Starry Night expects to see it. To work around this you should open the "Regional Settings" control panel, switch the date format to something other than the current setting, click OK, then reopen the "Regional Settings" control panel and switch to the UK day-month-year order. After restarting Starry Night it should be using the new date format. On the Macintosh you can reset the date format from the Date and Time control panel. After restarting Starry Night it should be using the new date format.

When I view from off the Earth, the time reads "UT". What does this mean?

UT is short for "Universal Time". This is the same thing as Greenwich Mean Time, and is the time in London, England (not accounting for daylight savings time). Universal Time is used as a standard reference time for astronomical events by astronomers around the world. When you are viewing from a location off the Earth, your old "time zone" does not really apply, so Starry Night uses Universal Time.

Does Starry Night use the Gregorian or Julian calendar for old dates?

Starry Night uses the old Julian calendar for all dates before Oct. 15, 1582, and the Gregorian calendar for all dates more recent than this. The dates Oct. 5-Oct. 14, 1582 do not exist in Starry Night, to account for the ten days which were skipped when the new calendar was introduced.

How do I find the time & date of eclipses?

Choose Sky->Interesting Events from the menu. A window should open which has all lunar and solar eclipses from 1901 to 2100, sorted by date. Click "Local View" to watch the event from your home location, or "Best View" to view from an ideal location.