Get the List of available Web Programmes in a Date Range that have been created or modified since a date. 

This is a listing of all of the Programmes created or modified since a date, for which there is a web occurrence starting within the date range and having available places. 

Only Programmes that have been created or modified after the supplied sinceDate will be returned. A Programme will be considered to be modified if it, any of its web occurrences with available places, or any of those occurrence's classes, units or prices, have been created or modified. 

Web occurrence means an occurrence which is published on the web. 

A date range is passed as two parameters, startDate and endDate, which define the end points of the date range. These are DateTime objects where the time component is significant. They must be populated with sensible dates (Start > End, is not considered sensible), otherwise, an input error results. 

The test for web occurrence start date, being within the date range, is inclusive of end points. 

Available places means that the number of students enrolled is less than the maximum number allowed for the occurrence. 

Each Programme item is represented by a TProg. The collection of Programme items is represented by a List of TProg. 

A token is passed for authentication. If the authentication fails, or other errors occur, no programmes are returned. The result of the authentication is represented by a TAuthenticate object. 

Requires a valid registration key entry for the Short Courses feature. 

This function has security level "Protected", and can only be accessed by users that have explicitly been granted permission to the API.

[WebMethod(Description = "Gets a list of programmes that have been created or modified since a date and have a web-enabled occurrence in the specified date range that has available places")]
public TAuthProgList GetWebProgrammesForDatesSince(string token, DateTime startDate, DateTime endDate, DateTime sinceDate);