4.3. Builtin Atomic Types
A number of builtin Atomic Types are predefined. Most of them have counterparts in XML Schema 1.1, because they are very useful also in JSON (for example : dates, times, ...). In particular, they have the same value space, the same lexical space, the same lexical mapping and (for primitive types) the same associated set of atomic facets.
Some of these builtin types are primitive and marked as such below. Others are derived from another builtin type.
The lexical namespace of dateTime as defined in XML Schema 1.1 is a superset of the date representation defined in
ECMAScript. In addition, JSound extends the lexical representation of respectively date, time, dateTime defined above, to allow the format defined in
RFC 2822 (nonterminals date, time, date-time respectively). This is because many JavaScript implementations do so.