Entering a Time Zone

Time zones may be selected either by using the Zone button to display the "Time Zone Selection" screen, or by entering a time zone mnemonic or a time directly into the Zone box.

You can enter standard time zones, Local Mean Time or Local Apparent Time.

•Standard Time Zones – These are standards that were adopted by various authorities in order to ensure that all people living in the same region used the same time standard.

•Local Mean Time (LMT) – This is the standard time of the longitude of a location. This was used in most places prior to the adoption of standard time zones. Using this standard, the mean position of the Sun is on the meridian at noon, but note that the true Sun varies from this position by up to about 15 minutes either way.

•Local Apparent Time (LAT) – This is the time according to the true position of the Sun in its diurnal arc, which is equivalent to sundial time. By this standard, noon occurs on each day when the Sun is exactly on the meridian. This is the standard that was generally used prior to LMT.

>> To enter a time zone using its mnemonic abbreviation

•Enter one of the standard 3 or 4 letter time zone abbreviations (e.g. “EST”, “AEST”, “BST”, “CWT”, etc.).

For the program to recognize the abbreviation, it must be in Solar Fire’s internal time zone database. If the abbreviation is not recognized, you will see an error dialog box, and you can try again. If it is recognized, then the corresponding zone time will be automatically appended after the abbreviation in the Zone box.

>> To enter a time zone using its time offset

•Enter the number of hours (and optionally minutes and seconds) from Universal Time or Greenwich Mean Time e.g. +8 or 8 for Pacific Standard Time, or -10:30 for Australian Central Daylight Time. For zones west of Greenwich, use a plus (+) sign or no sign. For zones east of Greenwich, use a minus (-) sign. You must use a colon(:) to separate hours minutes and seconds.

>> To enter Local Mean Time

•Type “LMT” into the Zone box.

The correct zone time for the current longitude will be appended after the abbreviation in the Zone box, and if you subsequently alter the longitude, this zone time will be amended automatically.

>> To enter Local Apparent Time (Sundial Time)

•Type “LAT” into the Zone box.

The correct zone time for the current date and location will be appended after the abbreviation in the Zone box, and if you subsequently alter the longitude or date, this zone time will be amended automatically.

>> To choose a time zone from the database of time zones

•Select the Zone button.

This will display the "Time Zone Selection" dialog box from which a time zone may be selected.

You can alter the order in which entries are shown by selecting the Sort Order as follows...

•Full Name - the records will be sorted into ascending alphabetical order of their full descriptive name.

•Zone Time - the records will be sorted into numerical order by their hours from GMT. (Note that the ordering is from 0 to 12 positive numbers followed by 0 to 12 negative numbers).

•Mnemonic - the records will be sorted into ascending alphabetical order of their mnemonic abbreviation.

>> To retrieve time zone details to the screen from which the Zone button was selected

1.Select the desired time zone entry from the list box

2.Click on the Select button.