Expression is used only for dates or date spans spelled out in full year/month (and in rare cases day) form, e.g. 2009 September-2010 February, or 1980s, or if using “circa” to indicate uncertainty about dates, e.g. circa 2000-2010. This field is not used if the single date or date range is a simple YYYY or YYYY-YYYY format. If two dates exist for a collection separate with a comma or semi-colon and then fill in the inclusive dates - example 1965; 2009.
Examples
1903, 1950-1955
circa 1952-1978
circa 1975 August
1892 or 1893
before 1920
after 1920
2015 Fall
2009 April 5 - 2010 May 1
For undated material:
Use sparingly. Use circa to estimate the date range, if the creation date is truly unknown use "undated", do not use n.d.
Type
Choose the appropriate option from the drop down menu.
Option
When Used
Bulk Dates
Rarely used at file level. Creation dates applicable to the majority of materials in the description level, excluding any outliers on either end.
Inclusive Dates
Creation dates applicable to all materials in the accession, including outliers on either end.
Single
Use if there is only one creation date for all materials in the unit described.
Begin
Numerical value of earliest (or only) creation date in the accession in YYYY, YYYY-MM, or YYYY-MM-DD format.
Examples
2018-01-01 (in expression field: 2018 January 1)
1975-05
1998
End
Numerical value of latest creation date in the accession in YYYY, YYYY-MM, or YYYY-MM-DD format.
Certainty
Choose “Approximate” from the drop down menu if dates are uncertain for any reason.