Appendix 2: Time Control Script Reference

Time Control Scripts

Alcyone Ephemeris performes all ephemeris calculations by use of a list, which holds all time statements to compute ephemeris data for (time control list). Time control lists are created by time control scripts , written a Pascal-like scripting language.

Each Alcyone Ephemeris file contains a time control script, which is executed when a new ephemeris calculation starts. The script is generated automatically when the Time span dialog was used, but can be written and edited manually too (see The Time Control Window).

Time Control Scripting Language

The scripting language includes the standard Pascal control structures with reserved words (such as if, then, else, while, repeat, and for ), procedures, functions, and expressions. For more information on standard Pascal see http://www.pascal-central.com or http://en.wikipedia.org/

The primary purpose of a time control script is to fill the time control list and to define other time-relevant settings (e.g. time shift, time scale). Therefore the scripting language offers some special procedures and variables, which are explained under Time Control List Procedures and Variables. In addition procedures and functions for astronomical calculations, date and time calculations and simple user interaction are defined.

When a time control scripts starts, the time control list is cleared and default values are assigned to all predefined variables.

For more information and script examples see:

Time Control List Procedures and Variables

Date and Time Calculations

Astronomical Calculations

Time Interval Constants

Time Shift Constants

Standard Epoch Constants