Defines the time period of Agent involvement in the Event. Can be either defined by start and end dates/times or duration.
• Format for date is: CCYY-MM-DD
• Format for time is: hh:mm:ss
• Format for duration is: P[yY][mM][dD][T[hH][mM][s[.s]S]]
See also : Core Vocabularities Specification for "Period"
Date (e.g. 27th October year 2013): 2013-10-27
Time (e.g. 20 minutes and 45 seconds past noon): 12:20:45
Duration (e.g. 7 years, 3 months, 8 days, 8 hours, 31 minutes and 52.05 seconds): P7Y3M8DT8H31M52.05S