@Colin Brough , Documentation sys  (https://docs.intersystems.com/healthconnect20211/csp/docbook/DocBook.UI....)   - "When it is time to start, if the item is enabled, the scheduler starts it; when it is time to stop, if the item is running, the scheduler stops it."

Production item will active between start and end time but it is can be controlled (to some extent) by the production component implementation.  We have a service that process files from a folder using the file adapter and it is using the schedule functionality. Schedule is set to start at 22:00 and stop at 23:00. Everyday service start at 22:00 and once it finish processing all files from the folder it remain inactive until next day 22:00. In our case since the file copy to the folder from external system only happens during the day time, when the service is started it is same as running service just once between 22:00 and 23:00. 

Hope that helps. 

May be you could try simply passing message to the required namespace:

  • Create two operations in the current namespace
  • Configure one of the operation as TCP connection to a business service in the second namespace where you have the required operation(see sample config) 

  • Configure the business service in the second namespace as pass-through to the required operation in that namespace