The Duration attribute is used to define a time interval. It is from the standard XML schema Duration type (XSD:Duration).

The time interval is specified in the following form "PnYnMnDTnHnMnS" where:

•P indicates the period (required)

•nY indicates the number of years

•nM indicates the number of months

•nD indicates the number of days

•T indicates the start of a time section (required if you are going to specify hours, minutes, or seconds)

•nH indicates the number of hours

•nM indicates the number of minutes

•nS indicates the number of seconds.

To specify a negative duration, enter a minus sign before the P.

“P5Y” for a period of five years.

“PT15H” for a period of 15 hours.

“-P10D” for a period of -10 days (useful when combined to an End Date.