Date or Period

When was the object made (e.g., 1893, early 17th century, Late Bronze Age)?
Relatively few objects can be dated with precision. It is common, therefore, to indicate age by date ranges (e.g., 1876-1878), parts of centuries (e.g., third quarter of the 18th century, late 14th century), regnal or dynastic periods (e.g., Victorian, Yuan dynasty), or cultural periods (e.g., Neolithic). No agreed rules exist for the terms used to qualify dates, but the following suggestions are offered as a guide:

probably   for fairly certain dates
circa (ca.)  ten years on either side of the date
flourished (fl.)  twenty years on either side of the date (describing the maker not the object)
before  up to 100 years before the date given
after  up to 100 years after a date

When date ranges (sometimes called date spans) are used, the first date should be the earliest date, within reason, that the object could have been made and the latter the latest possible date. Period names specific to one country (e.g., US Federal, UK Regency) are best avoided when providing information for international circulation.

Some objects may have been created in one period and substantially altered at a later date. In these cases both the date or period of creation and the date or period at which the alterations were made should be recorded (e.g., early 17th century, reworked 1879). An object or objects made in one period may be incorporated into an object made in another, as is the case with the gold intaglio bracelet mentioned earlier at the end of Type of Object: Gold intaglio bracelet set with 13 cornelian and hardstone intaglios, mostly Roman 1st to 3rd century AD, the intaglios mounted in gold, circa 1820. In these cases all relevant dates should be provided.