Step Size Specification

There are three types of step size specification:

1. as a statement of days, hours, minutes, and seconds
2. as a decimal number of days
3. as a numerical expression representing the number of days

Specification as a statement of days, hours, minutes, and seconds

The step size is expressed as a statement of days, hours, minutes, and seconds in the form [DDd] HH:MM[:SS]. Days and seconds are optional. Values between 00:00:01 (1 second) and 100000 days are accepted.

Examples:

The step size is specified as 1 day. 101 ephemeris calculations will be performed in intervals of 1 day, starting -245-01-01.	The step size is specified as 15 minutes. 97 ephemeris calculations (1440/15+1) will be performed starting 2008-02-17 12:00.

Specification as a decimal number of days

The step size is expressed as a decimal number of days. Values between 1/86400 (1 second) and 100000 days are accepted.

Examples:

The step size is specified as 0.05 days. 21 ephemeris calculations will be performed in intervals of 0.05 day, starting 2008-01-08.	The step size is specified as 365.2421897 days (tropical length). 92 ephemeris calculations will be performed, starting  at spring equinox 2008 (2008-03-20).

Specification as a numerical expression

The expression is representing a the number of days . Values between 1/86400 (1 second) and 100000 days are accepted. Within the expression all variables, constants, and functions of the time control scripting language may be used (see time control script reference)

Examples:

The step size is specified as 1/100 day (864 seconds). 101 ephemeris calculations will be performed in intervals of 1/100 day, starting 2008-01-07.	The step size is specified as 1/100 of the covered time span. 101 ephemeris calculations will be performed. For the meaning of JD1 (end time) and JD0 (start time) see  time control script reference)