| 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">AD 56</date>
 <date when="-0056">56 BC</date>
 |  
                                    | This list begins inthe 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, butyyyy,--mm,---dd,yyyy-mm, or--mm-ddmay also be
                                          	  used. For the time part, the formhh:mm:ssis
                                          	  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. |  |  |