| Attributes | In addition to global attributes| period | supplies a pointer to some location defining a named
      period of time within which the datable item is understood to
      have occurred. |  | when | supplies the value of the date or time in a standard form,
      e.g. yyyy-mm-dd.| Status  | Optional |  | Datatype  |  |  | Values  | A normalized form of temporal expression conforming to the W3C
	XML Schema Part 2: Datatypes Second Edition. |  Examples of W3C date, time, and date & time formats. <date when="1945-10-24">24 Oct 45</date> <date when="1996-09-24T07:25:00Z">September 24th, 1996 at 3:25 in the morning</date> <time when="1999-01-04T20:42:00-05:00">Jan 4 1999 at 8 pm</time> <time when="14:12:38">fourteen twelve and 38 seconds</time> <date when="1962-10">October of 1962</date> <date when="--06-12">June 12th</date> <date when="---01">the first of the month</date> <date when="--08">August</date> <date when="2006">MMVI</date> <date when="0056">56 AD</date> <date when="-0056">56 BC</date>  |  This list begins in  the year 1632, more precisely on Trinity Sunday, i.e. the Sunday after  Pentecost, in that year the <date calendar="Julian" when="1632-06-06">27th of May (old style)</date>.  |  <opener>  <dateline>   <placeName>Dorchester, Village,</placeName>   <date when="1828-03-02">March 2d. 1828.</date>  </dateline>  <salute>To    Mrs. Cornell,</salute> Sunday <time when="12:00:00">noon.</time> </opener>  |  | Note | The value of the when attribute should be the
        normalized representation of the date, time, or combined date
        & time intended, in any of the standard formats specified
        by XML Schema Part 2: Datatypes Second Edition, using the Gregorian calendar.  The most commonly-encountered format for the date part of the when
attribute is  yyyy-mm-dd, but
	  yyyy, --mm, ---dd,
	  yyyy-mm, or --mm-dd may also be
	  used. For the time part, the form hh:mm:ss is
	  used.  Note that this format does not currently permit use of the
	  value 0000 to represent the year 1 BCE; instead
	  the value -0001 should be used.   |  
  |  | notBefore | specifies the earliest possible date for the event in
	  standard form, e.g. yyyy-mm-dd.| Status  | Optional |  | Datatype  |  |  | Values  | A normalized form of temporal expression conforming to
	the W3C XML Schema Part 2: Datatypes Second
	Edition. |  
  |  | notAfter | specifies the latest possible date for the event in
	  standard form, e.g. yyyy-mm-dd.| Status  | Optional |  | Datatype  |  |  | Values  | A normalized form of temporal expression conforming to the W3C
	  XML Schema Part 2: Datatypes Second Edition. |  
  |  | from | indicates the starting point of the period in standard form, e.g. yyyy-mm-dd.| Status  | Optional |  | Datatype  |  |  | Values  | A normalized form of temporal expression conforming to
	  the W3C XML Schema Part 2: Datatypes Second
	  Edition. |  
  |  | to | indicates the ending point of the period in standard
	  form, e.g. yyyy-mm-dd.| Status  | Optional |  | Datatype  |  |  | Values  | A normalized form of temporal expression conforming to
	  the W3C XML Schema Part 2: Datatypes Second
	  Edition. |  
  |  
  |