Dates can appear in generated documents through 3 different ways:
In the latter case, when the date is automatically filled in, the date can be tied to either a signature or document.
If the automatic date is tied to a signature, then it will simply be the date of the signature.
If the automatic date is tied to a document, then it will be the date that the document is finalized. Documents are only finalized when the entire document set is finalized. Document sets can be set to finalize either automatically or manually, for each participating individual.
If a document set is set to automatically finalize for everyone, then it will finalize immediately once all signatures for all documents have been provided. Otherwise, if a document set is set to manually finalize for a given person, then it will finalize only after the signatures have been provided, and then explicitly released by that person (in a separate step).