The rebuilding of the document can be triggered in 3 ways...
01
SCHEDULED
You decide the date and time that the rebuild occurs. This can be weekly, daily, monthly, etc. The document is rebuilt even if there are no changes.
02
ON CHANGE
When the system detects that the source document has changed, signalling new data has been added or changed, then the rebuild is triggered. Editing a document triggers the rebuild just after midnight.
03
ON DELETE
If you delete the PDF on your side, then the server triggers a rebuild and replaces the PDF with a new document. Deleting the PDF triggers the rebuild just after midnight.