Web Service support for Site Workflow scheduling
Currently the nintex web service supports WF scheduling for documents and list items, would be great to also have site workflow supported as well.
Vadim Tabakman commented
If you call the AddWorkflowSchedule web method and not put in a url to a document, then it will assume you are trying to add a schedule a site workflow.
Optional. The absolute or relative URL of the file on which to add or update a workflow schedule for reusable or list workflows. If a relative URL is specified, the URL must be relative to the current SharePointwebsite.
To add or update a workflow schedule for site workflows, do not specify a value for this parameter.