Proposals

Last updated November 18, See Change Log

This page lists suggested new features to be considered for addition to EDTF. Many (but not all) are the result of distilling the Dublin Core DCMI Date and Time Representation Requirements. (Several of the features on that page are already supported by EDTF, and are not covered here.)

Any of these may or may not be incorporated into EDTF, depending on need and complexlity. There are two criteria:

• There should be implementers and users who would (respectively) implement and use the feature.
• Incorporation and implementation of the feature should not require unreasonable complexity and expense.
  

Implementers and users are encouraged to comment on these feature. No feature will be implemented that nobody speaks up for. There is a listserv dedicated to discussion of this.

Proposed Feature List

1. Abstract dates/times
   E.g.
• 4 July
  Specifying the (recurring) date of a particular holiday.
• 8pm
  Specifying the (recurring) time of a television program .
• 3 weeks
  Specifying the typical period of recovery time for a hamstring injury.
  
  
  
2. Standard periods
   E.g.:
• Millennium
• Century
• Week (of year)
• Day (of year)
  



3. Named periods/event
   E.g.
   • World War 1
     
   • Jurassic period
     
   • Big Bang
     
   • Baroque
   • Tang Dynasty
     
     
     
4. Named period as the endpoint of a range
   E.g.
   
   • From the Big Bang to the Jurassic Period.
     
     
     
5. Multiple, individual dates or times considered to be components of a single event
   E.g.
• "The hearing was held on the 3rd, 5th, and 9th-12th October 2002."
  
  
  
6. Alternative definitions of year, month, day, etc.
   E.g.
• Solar year
  the time it takes a planet to rotate around its Sun star.
• Lunar month
  the time it takes a moon to rotate around its planet.
• In some cultures a day begins at sunset (as opposed to midnight).
  
  
  
7. Endpoint of a precision component
   E.g.
• 1 January 2000, 00:00
  midnight at the beginning of 1 January 2000
• 1 January 2000, 24:00
  midnight at the end of 1 January 2000
• T01:60:60
  the end of the hour beginning at 1am
• T02:00:00
  the beginning of the hour beginning at 2am
  
  
  
8. Extension times
   e.g.
• 26th hour of a day
  
  
  
9. Some of the date or time is approximate but the event occurred within a known period.
   e.g.
• "The event will take place on 12th March 2003, at around 14:00."
  
  
  
10. Duration of event less than that of an interval
    e.g.
    • "The machine was used for a total of 3 hours between 8am and 6pm on 12 June 1999."
      
      
      
11. The endpoint of a range is another range
    For example the start point of the range is known, but the end point cannot be pinned down to an exact date/time but is within a known range.
    E.g.
• "The festival will begin 12th March, 2003, and end between 19 March and 20 March, 2003."
  
  
  
12. Years containing more than four digits
    (Years containing more than 4 digits are only valid in ISO 8601 with special, prior agreement, and the number of digits must be fixed for ALL dates within that agreement.)
    e.g.
• Homo sapiens idaltu fossils dating from 160000 BCE
• A science fiction novel set in the future in the year 25002 CE
  
  
  
13. Non-Gregorian dates
    
    
    
14. Seasons (and standard parts of year)
    E.g.
    • Spring 2000
    • Spring 2000 (Southern Hemisphere)
    • First Quarter, 2000
      
      
      
15. Before/after indicator
    E.g.
    • <1760-12-03
      "The event occurred sometime before December 3, 1760."
    • >1760-12
      "some month after December 1760"
    • >1760
      "some year after 1760"
    
    
16. Internal "questionable"
    "Questionable" is already supported by appending a question mark, e.g. "2004?". However, consider the case where the specific date within the year is known, and the decade is known, but not the specific year.  e.g. '156?-12-25'  to mean "December 25 sometime during the 1560s". 
    
    
17. Holidays with no fixed date
    For example: "Easter, 2009", "Passover, 2009". (And represent the difference between the western and eastern easters.)
    
    
18. represent uncertainty by a range
    For example, you don't know when the event ocurred but you have narrowed it down to between 2000 and 2008. There is already a range function, e.g.  2000/2008 means the period 2000-2008, which is quite different semantics. But we could, for example, enclose the range in brackets, e.g. [2000/2008] or something similar, to represent this. Furthermore even this assertion could be "questionable" or "approximate". So for example you could say:
    • [2000/2008]   the event occurred between 2000 and 2008
    • [2000/2008]~ the event occurred approximately between 2000 and 2008, or even:
    • [2000/2008]? we think the event occurred between 2000 and 2008 but we're not sure
      

Change Log

This page was created October 5, 2005.

Modified:

• October 6. #15 added.
• October 7. #16 and 17 added.
• November 13. #18 added.
• November 18. Typos fixed. (See message.)

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