Deadline and Duration Expressions

To specify deadlines and durations for activities, BPEL uses lexical representations of corresponding XML Schema data types. For setting deadlines, the data types are either dateTime or date. For setting the duration (a timeout, for instance), you can use the duration data type. The lexical representation of expressions should conform to the XPath 1.0 (or the selected query language) specifications. Such expressions should evaluate to values of corresponding XML Schema types: dateTime and date for deadline and duration for duration expressions.

All three data types use lexical representations that conform to the ISO 8601 standard. For more information on this standard, see the ISO web page at http://www.iso.ch. The ISO 8601 lexical format uses characters within date and time information. Characters are appended to the numbers and have the following meaning:

• C represents centuries.

• Y represents years.

• M represents months.

• D represents days.

• h represents hours.

• m represents minutes.

• s represents seconds. Seconds can be represented in the format ss.sss to increase precision.

• Z is used to designate Coordinated Universal Time (UTC). It should immediately follow the time-of-day element.

For the dateTime expressions, there is an additional designator:

• T is used as a time designator that indicates the start of the representation of the time.

For duration expressions, the following characters can also be used:

• P is used as the time duration designator. Duration expressions always start with P.

• Y represents the number of years.

• M represents the number of months or minutes.

• D represents the number of days.

• H represents the number of hours.

• S represents the number of seconds.