Timespan and Units of Time

19 Sep 2020 

Timespan and Units of Time.

Gordon Dunsire, Technical Team Liaison Officer. 

This paper proposes adjustments to treatment of the entity Timespan and associated elements in the beta RDA Toolkit to resolve a conflict with the IFLA Library Reference Model and to improve clarity, coherency, and consistency of the guidance and instructions.

A paper discussion at the October 2020 RDA Steering Committee (RSC) meeting.

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4 Responses to Timespan and Units of Time

  1. Thomas Dousa says:

    This is a small editorial note on the text of this document. On page 2 of the document, in lines 3-4 from the top of the third paragraph in the section on “Timespan granularity”, the phrase “In principal, …” should be changed to “In principle, …”.

  2. Ryan Tamares says:

    Comment from AALL:

    From a bibliographic point of view, catalogers are interested in points of time that may be identified with varying degrees of precision, e.g., a day, a month, a year. The need to specify times more precise than a day or less precise than a year is rare, in terms of RDA (and not in terms of subject cataloging). RDA would do better to reference other standards, such as ISO 8601-1:2019 (definitions freely available at https://www.iso.org/standard/70907.html – click “Preview”). The utility of this document, among others forming new RDA, is of much concern—will catalogers be able to use these in their day-to-day work?

  3. Keith Knop says:

    Comments from MLA:
    It’s not clear what the phrase “real world” means on page 3. From context, it seems to be referring to the “world” of vernacular usage of calendrical units? It’s a strange phrase to use here.

    Not specific to this paper, but is Wikipedia really the best available source for an international organization to use in creating their definitions? Notably in this case while there is a citation to the Wikipedia article for Second, the proposed definition for “second” is in line with the International System of Units (SI) definition–yet this is not referenced anywhere in the paper or identified in the definition. Without that information the definition otherwise seems arbitrarily complex.

    The desire to have units defined in terms of the next-smallest unit is understandable but produces some very soupy–if not backwards–definitions for month and year. Characterizing a year as “approximately 12-13 months” implies that it could be a non-integer value of months. According to the cited Wikipedia article for Month, all 25 discussed calendar systems consist either of 12 months, 13 months, or 12 months with a periodic intercalary month. Why not actually say that? “…12 or 13 months, depending on the specific mechanics of the calendar system in use.”

    Why is “year” the only unit to receive an explanatory note in the definition table? Why not “month”?

    In terms of adding calendrical units to the RDA Glossary, Option 1B seems best. As the paper notes, option 1A would be expensive and time-consuming, and the paper doesn’t make a case for what benefits would be achieved from this new vocabulary encoding scheme.

    For the sake of curiosity, what is the use case for having “microseconds” defined as proposed in recommendation 5?

  4. Kathryn Lybarger says:

    I agree that “duration” is useful in RDA and not just in a way that is computed from a start-time and an end-time; a two hour film doesn’t start at midnight and end at 2am, it is just two hours long.

    I don’t think the full table of calendrical units with their definitions is needed within RDA; it seems unlikely to be useful to catalogers, and we can just point to an external standard for it. It could be helpful to mention variations in calendars, such as the 12/13 month aspect of the Hebrew calendar, but it gets buried (and not specified) when presented this way.

    In Recommendation 4/5, what are the standard abbreviations for these units of time? Are you talking about abbreviations like “sec.” or SI symbols like “s”? Would that be ms for millisecond? μs for microsecond?

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