There are two dates that are relevant. The creation date of the asset and a descriptive date relating to the content.
For the creation date, always input date information in the ISO 8601:2004 standard format: YYYY-MM-DD. This provides a consistent method for version tracking.
When digitising physical items, historic dates should be recorded in the description box. This allows for estimates (i.e. c1950) where an accurate date is not available.