Production answer · dates
Can the date field include circa or ranges?
Yes. The date line is controlled human-authored text, so it can preserve qualified wording such as “c. 1910,” “1948–1951,” or “date unknown.”
Why this matters
Keeping the display value as text avoids false precision and lets the team use its established editorial conventions.
A reviewable sequence
- Enter the exact reviewed public wording.
- Keep machine-sort dates in the authoritative catalog if needed.
- Record the basis in an internal source note.
- Compare date-line changes before reprinting.