REFINEMENTS &
ENCODING SCHEMES
|
Where and if appropriate, you may decide to use the specific date/time encoding rules established in the ISO 8601 profile of the international standard for the representation of dates and times:
(http://www.w3.org/TR/NOTE-datetime)
(http://www.w3.org/TR/xmlschema-2/#dateTime).
However, PBCore has determined that the pure ISO 8601 Profile and its current strict representational requirements in XML Schema Definitions are too restrictive.
PBCore recommends that you employ the syntax ISO 8601 suggests for entering dates (e.g., YYYY-MM-DD), but by no means is the entire Date+Time string required as you enter a date or time stamp for your media item. The date and/or time designated is essentially an open-ended text string with highly recommended syntax for entering years, months, and days. Examples are provided below. |
GUIDELINES
FOR USAGE
|
The descriptor dateAvailableStart refers to the beginning date that a version or rendition of a media item
is officially available for publication, broadcast or distribution.
A specific time may also be associated with the date.
To avoid problems in indicating date ranges for a media item's availability, PBCore has spawned two separate descriptors to capture specific dates that are independently searchable:
dateAvailableStart and
dateAvailableEnd
DATE FORMATTING:
PBCore recommends that you employ the syntax ISO 8601 suggests for entering dates (e.g., YYYY-MM-DD), but by no means is the entire Date+Time string required as you enter a date or time stamp for your media item. The date and/or time designated is essentially an open-ended text string with highly recommended syntax for entering years, months, and days.
The recommended format consists of a text string for the representation of dates YYYY-MM-DD
(1998-01-24).
- Year (YYYY) is defined as 0000 to 9999.
- Month (MM) is defined as 01 to 12.
- Day (DD) is defined as 01 to 28, 29, 30 or
31 as applicable.
- The separator between date fields is a hyphen,
(-).
If the full date is unknown, month and year (YYYY-MM)
or just year (YYYY) may
be used. Many other syntaxes are possible,
but if used, they may not be easily interpreted, searchable, or shareable.
If a date is approximate, add a question mark
but separate the date from the question mark by a space so that
the question
mark is not interpreted
as part of the date value by a search
engine, e.g., 1922 ? .
Generally, a year or year-month-day designation will provide enough precision.
If needed, a specific time stamp may directly
follow the date designation. The time stamp can be enclosed within parentheses. The time format (hh:mm:ss) consists of two digit
designations for hours, minutes and seconds (19:20:30) in a 24
hour clock mode. If necessary,
the seconds may be further defined by a
decimal fraction of a second (19:20:30.45).
ISO 8601 requests the inclusion of a time zone designator (TZD) to complete a date/time statement, but PBCore does not require or mandate that specification.
|