Risa,
Mendix does have a scheduler. You can read about scheduled events here: https://docs.mendix.com/refguide/scheduled-events#1-introduction I think if you combined this with a REST call (to get files from other systems) you will be able to accomplish what you need. REST call documentation can be found here: https://docs.mendix.com/refguide/consumed-rest-services#1-rest and here: https://docs.mendix.com/refguide/call-rest-action
Hope that helps,
Mike