When working with heritage inventories, historic archives, and archaeological site records, dates are some of the most important pieces of information that we manage. However, we often deal with instances in which our temporal data are “fuzzy”—sometimes we only have precision down to a month, a year, maybe even a century—sometimes we only have approximations or are uncertain about the information we do have on hand.

Some dates are difficult to decipher. Photo: National Museum of American History, "American Enterprise" Exhibition (2015)

Some dates are difficult to decipher. Photo: National Museum of American History, “American Enterprise” Exhibition (2015)

Computer systems such as databases typically don’t like fuzzy dates—they assume a level of certainty and precision that historic data are hard-pressed to match. But given a blank form field, humans aren’t very good at entering fuzzy date information in a consistent manner. The US Library of Congress has recognized these challenges and has drafted an extension to the ISO 8601 date standard they call the Extended Date/Time Format (EDTF).

Arches, an open source heritage inventory system, developed by the Getty Conservation Institute and the World Monuments Fund, is the first of its kind (and its class) at providing a standards-based inventory system specifically designed from the ground up for built heritage resources.

While learning how Arches works and testing it out in house, we found that adding EDTF support to Arches date fields would possibly benefit users who need to manage a wider range of dates in their inventory system: dates such as “about 1800” or date ranges such as “1934 – present”.

And because Arches is an open source system, we were able to seize the opportunity to develop the feature and contribute it to the growing Arches community!

You can access our more detailed documentation and download the code at our Github. And we welcome further contributions and issue reports there!