Cataloguing Dates

Do

• Use origDate for dates of origin, rather than date, in the origin section.
• Mark up any text that describes a date with origDate tags (or date if it isn't a date of origin of a manuscript of part of a manuscript.)
• Ensure that the text fully describes the date for display to users (e.g. include an indication of the calendar, such as by appending "CE" or "H"). This is what will be displayed on the web site. But it is not machine-readable, so you should also add attributes to the origDate element as described below, which will be used to index the manuscript so people can find it by its century (or centuries) of origin.
• Set the calendar attribute according to which calendar the text expresses the date in (e.g. '#Gregorian', '#Hijri-qamari'). If the text contains the date in two calendars, use the first, or consider splitting into two separate origDate elements.
• If a specific day, month or year is known, add a when attribute using the W3C date format (e.g. '1492', '1311-12', '1415-10-25') in the Gregorian calendar. If the date described by the text is in the Hijri-qamari calendar, convert that into the Gregorian date for use in the when attribute.
• If there is a range within which the manuscript (or part) originated, use notBefore and notAfter attributes, again with values that are W3C format dates in the Gregorian calendar. Also use those if the date is known to be a single year in one calendar, but that stretches across two years when converted into the Gregorian calendar.
• If only a beginning of a date range is known, use notBefore on its own. Likewise, if only a latest possible date for the origin of the manuscript (or part) is known, use notAfter on its own.
• If there are known specific dates for the beginning and end of production, use from and to attributes.
• If there is a gap between phases of creation (e.g. the text was created in the 13th century then illustrations added in the 15th century) then create two origDate elements.

Don't

• Do not set the calendar attribute according to the date expressed in the other attributes. These must always be Gregorian dates in order for the web site to index dates consistently for all manuscripts in the collections.
• When using two or more origDate elements to record the same date in two or more different calendars, do not use something like "Gregorian" for the text. Ensure that they all contain text which fully describes the dates such that, if the XML tags were stripped out, it would still make sense as a piece of text (e.g. "1043 H, 1633-1634 CE")
• Do not combine the when attribute with notBefore, notAfter, from, and to. If say a specific year is known, and then a date range for additions, explain that as a sentence, tagged up with multiple origDate elements.
• Do not mark up a statement that no date is known with origDate tags. Just include that as text within the origin element.
• Do not use attributes such as atLeast, atMost, min, or max - these are valid, but it is better to use the date-specific equivalents notBefore, notAfter, from, and to instead.
• Do not use the period attribute to record the calendar. It is for a named period of time (possibly the reign of a monarch or a war?)

Optionally

• Use the cert attribute to record the degree of certainty of the date (the value should be one of: 'low', 'medium', 'high', or 'unknown').
• If you want to include attributes specifying the dates in a calendar other than Gregorian, use notBefore-custom, notAfter-custom, from-custom and to-custom, but you must also include a datingMethod attribute indicating the calendar those dates are expressed in (even if it is the same as the calendar attribute.)

Examples

Bad:  <origDate when="575" calendar="#Hijri-qamari">19th Ramadan 575</origDate>
Good: <origDate when="1180-02-24" calendar="#Hijri-qamari">19th Ramadan 575</origDate>

Bad:  <origDate calendar="#Gregorian" notBefore="1272" notAfter="1273">671 H</origDate>
Good: <origDate calendar="#Hijri-qamari" notBefore="1272" notAfter="1273">671 H</origDate>

Bad:  <origin><origDate>No date</origDate></origin>
Good: <origin>No date</origin>