For any time-bound restrictions applied at the collection, series, or file or item level, add restriction begin and end dates. Dates must be entered in full ISO 8601 format (YYYY-MM-DD). If the exact date is unknown, follow the guidelines in the table below. 

• Set the restriction begin date to the creation end date of the material. 

• Restriction end dates should be set to 20, 50, or 75 years after the creation end date depending on the restriction type. (See Access Restrictions for more information on restriction periods.) If you only know the year when the material was created, not the month or day, add one year to the restriction end date (e.g. material created in 2020 with a 50-year restriction would have a restriction end date of 2071).