Note: because this type is defined as an extension of SXCM_T, all of the attributes and elements accepted for T are also accepted by this definition. However, they are NOT allowed by the normative description of this type. Unfortunately, we cannot write a general purpose schematron contraints to provide that extra validation, thus applications must be aware that instance (fragments) that pass validation with this might might still not be legal.

If a value is an exceptional value (NULL-value), this specifies in what way and why proper information is missing.

A quantity specifying a point on the axis of natural time. A point in time is most often represented as a calendar expression.

Specifies whether the limit is included in the interval (interval is closed) or excluded from the interval (interval is open).

A code specifying whether the set component is included (union) or excluded (set-difference) from the set, or other set operations with the current set component and the set as constructed from the representation stream up to the current point.

A prototype of the repeating interval, specifying the duration of each occurrence and anchors the periodic interval sequence at a certain point in time.

A time duration specifying as a reciprocal measure of the frequency at which the periodic interval repeats.

Specifies if and how the repetitions are aligned to the cycles of the underlying calendar (e.g., to distinguish every 30 days from "the 5th of every month".) A non-aligned periodic interval recurs independently from the calendar. An aligned periodic interval is synchronized with the calendar.

Indicates whether the exact timing is up to the party executing the schedule (e.g., to distinguish "every 8 hours" from "3 times a day".)