Data Property: F6Design:hasRecurrence

rdfs:comment "For recurrence intervals use duration of interval with format 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 Example: P5Y2M10DT15H The example above indicates a period of five years, two months, 10 days, and 15 hours." (en)

http://archive.astro.umd.edu/Ontology/F6/OWL/F6Design.owl#hasRecurrence