This value type is used to identify values that contain a precise period of time.
This value type is defined by the following notation:
period = period-explicit / period-start
period-explicit = date-time "/" date-time ; [ISO.8601.2004] complete representation basic format for a ; period of time consisting of a start and end. The start MUST ; be before the end.
period-start = date-time "/" dur-value ; [ISO.8601.2004] complete representation basic format for a ; period of time consisting of a start and positive duration ; of time. Description: If the property permits, multiple "period" values are specified by a COMMA-separated list of values. There are two forms of a period of time. First, a period of time is identified by its start and its end. This format is based on the [ISO.8601.2004] complete representation, basic format for "DATE- TIME" start of the period, followed by a SOLIDUS character followed by the "DATE-TIME" of the end of the period. The start of the period MUST be before the end of the period. Second, a period of time can also be defined by a start and a positive duration of time. The format is based on the [ISO.8601.2004] complete representation, basic format for the "DATE-TIME" start of the period, followed by a SOLIDUS character, followed by the [ISO.8601.2004] basic format for "DURATION" of the period.
The period starting at 18 ending at 07:00:00 UTC on January 2, 1997 would be:
The period start at 18:00:00 on January 1, 1997 and lasting 5 hours and 30 minutes would be:
No additional content value encoding (i.e., BACKSLASH character encoding, see Section 3.3.11) is defined for this value type.