"date" Datatype Values and Representations

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∟"date" Datatype Values and Representations

This section describes the built-in primitive datatype, 'date' that represents dates in Gregorian calendar. Leading and trailing whitespaces are allowed and trimmed. Timezone offset is optional.

The "dateTime" datatype can be easily divided into 2 datatypes:

"date" - Using "year", "month" and "day" properties only to represent dates.
"time" - Using "hour", "minute" and "second" properties only to represent moments of time within a day.

Let's look at "date" first in this tutorial.

"date" is a built-in datatype that uses the date/time seven-property model to represent a date in the Gregorian calendar system with these rules:

The value space of "date" is all possible dates in Gregorian calendar with "year" in the range of -2147483648 and 2147483647.
The lexical space of "date" is all possible "date" values represented in (year)-(month)-(date)(timezoneOffset)? patten.
"year", "month" and "date" are required properties.
"timezoneOffset" property is optional and no default timezone is defined.
Leading and trailing whitespaces allowed and trimmed.

To verify these rules, I wrote this simple XSD document that uses "date" datatype to declare XML elements:

<?xml version="1.1"?>
<!-- date_datatype_test.xsd
 - Copyright (c) 2002-2013 HerongYang.com. All Rights Reserved.
-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="Date_Datatype_Test">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="Date" type="xs:date"
        maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
</xs:schema>

Here is a sample XML document that can be used to test these declarations:

<?xml version="1.1"?>
<!-- date_datatype_test.xml
 - Copyright (c) 2002-2013 HerongYang.com. All Rights Reserved.
-->
<Date_Datatype_Test>

<!-- 4 valid "Date" elements -->
  <Date>   1971-05-16Z   </Date>
  <Date>   0001-05-16Z   </Date>
  <Date>   -1971000-05-16  </Date>
  <Date>-0123-05-16-05:00</Date>

<!-- 4 invalid "Date" elements -->
  <Date>        05-16  </Date>
  <Date>   1971-05-16T00:00:00  </Date>
  <Date>     12-05-16   </Date>
  <Date>001234-05-31</Date>
</Date_Datatype_Test>

When validating this XML document with my XsdSchemaValidator.java program presented earlier in the book, I get 4 groups of errors for 4 invalid XML elements:

herong> java XsdSchemaValidator
^^^ date_datatype_test.xsd date_datatype_test.xml

Error:
   Line number: 14
   Column number: 31
   Message: cvc-datatype-valid.1.2.1: '05-16' is not a valid value
   for 'date'. (Missing "year")

Error:
   Line number: 14
   Column number: 31
   Message: cvc-type.3.1.3: The value '        05-16  ' of element
   'Date' is not valid.

Error:
   Line number: 15
   Column number: 40
   Message: cvc-datatype-valid.1.2.1: '1971-05-16T00:00:00' is not a
   valid value for 'date'. ("time" not allowed)

Error:
   Line number: 15
   Column number: 40
   Message: cvc-type.3.1.3: The value '   1971-05-16T00:00:00  ' of
   element 'Date' is not valid.

Error:
   Line number: 16
   Column number: 32
   Message: cvc-datatype-valid.1.2.1: '12-05-16' is not a valid value
   for 'date'. ("year" must have 4 digits or longer)

Error:
   Line number: 16
   Column number: 32
   Message: cvc-type.3.1.3: The value '     12-05-16   ' of element
   'Date' is not valid.

Error:
   Line number: 17
   Column number: 28
   Message: cvc-datatype-valid.1.2.1: '001234-05-31' is not a valid
   value for 'date'. ("year" with more than 4 digits can not have
   leading 0)

Error:
   Line number: 17
   Column number: 28
   Message: cvc-type.3.1.3: The value '001234-05-31' of element 'Date'
   is not valid.

Failed with errors: 8