If you select one of the cities from the list,
the city you choose will be displayed in the SELECTED box, ALL necessay
data will be input for you AND the calculations will be done autonatically.
An important thing to watch out for here is the Hour Offset. The
Hour Offset displayed and used for the calculations is Standard Time.
If the city is currently observing Daylight Time you will have to DECREASE
the Hour Offset by 1.
You can get precise latitude and longitude values
at Maporama . Input the value as
positive. The N button next to the Latitude and the W button next to Longitude
are toggle switches. If you are in the Southern Hemisphere click the N
and it will change to S. The same thing applies to the W button to change
it to E.
Hour Offset is the number of hours your local time is different from Universal Time (Greenwich Mean Time). The program places a value there, as well as the Date, based upon your computer's clock, however, for numerous reasons it may not be accurate.
The clock that shows at the top of the page 
should help. That shows the UTC time when the page was loaded.
Find the difference, in hours, between your local time and that value. If you are in the Eastern Hemisphere you MUST consider it a NEGATIVE value.
2. Once the correct values have been placed
in the boxes hit 
and the information should
show up in the other boxes.
3. The + and - buttons may be used to increment by 1 the Latitude, Longitude, Hour Offset, Month and Day. However:
4. The Clear buttons 
do what they say and your data will have to be input again.
* Thanks to Rob Garrett for suggesting the UTC clock. I hope that you find it useful. If you have any questions concerning this program please don't hesitate to e-mail me.
Use your Back button to return to the main program.