4.3.9 Period of Time
Basic Definition | Formal Definition | Description| Example
Basic Definition
- Value Name
- PERIOD
- Purpose
- This value type is used to identify values that contain a precise period of time.
Formal Definition
The data type is defined by the following notation: period = period-explicit / period-start period-explicit = date-time "/" date-time ; [ISO 8601] 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] 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 character (US-ASCII decimal 44) 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 expressed as the [ISO 8601] complete representation, basic format for "DATE-TIME" start of the period, followed by a SOLIDUS character (US-ASCII decimal 47), 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 expressed as the [ISO 8601] complete representation, basic format for the "DATE-TIME" start of the period, followed by a SOLIDUS character (US-ASCII decimal 47), followed by the [ISO 8601] basic format for "DURATION" of the period.
Example
The period starting at 18:00:00 UTC, on January 1, 1997 and ending at 07:00:00 UTC on January 2, 1997 would be: 19970101T180000Z/19970102T070000Z The period start at 18:00:00 on January 1, 1997 and lasting 5 hours and 30 minutes would be: 19970101T180000Z/PT5H30M No additional content value encoding (i.e., BACKSLASH character encoding) is defined for this value type.