date data type

The xs:date data type represents an interval of exactly one day in duration that begins on the first moment of a specific day. The xs:date data type consists of year, month, and day properties that are expressed as integer values and an optional time zone indicator. Derived from the xdt:anyAtomicType data type.

Time-zoned values of type xs:date track the starting moment of the day, as determined by the timezone. The first moment of the day begins at 00:00:00, and the day continues until, but does not include, 24:00:00, which is the first moment of the following day. For example, the first moment of the date 2002-10-10+13:00 is the value 2002-10-10T00:00:00+13:00. This value is equivalent to 2002-10-09T11:00:00Z, which is also the first moment of 2002-10-09-11:00. Therefore, the values 2002-10-10+13:00 and 2002-10-09-11:00 represent the same interval.

The lexical form of xs:date is a finite-length sequence of characters of the following form: yyyy-mm-ddzzzzzz. Negative dates are not allowed. The following abbreviations are used to describe this form:

yyyy: A 4-digit numeral that represents the year. Valid values are from 0001 through 9999. A plus sign (+) is not allowed.
mm: A 2-digit numeral that represents the month.
dd: A 2-digit numeral that represents the day.
zzzzzz: Optional. If present, represents the timezone. See Timezone indicator for more information about the format for this property.