Hi Dan,

Are these going to be one time only schedules each time (meaning they do not recur)?  If so, have you looked into Outages? 

https://docs.servicenow.com/bundle/london-it-service-management/page/product/service-portfolio-manag...

There is already a lot of functionality built into them, which may help to accomplish what you are looking to do.  Just thought I would bring that up as another option.