This implies that a time interval can be open-ended - i.e., a time interval can have only the start date.
However, the usage note of dcterms:PeriodOfTime in DCAT allows also for time intervals having only the end date - quoting from §6.15 Class: Period of Time:
The start and end of the interval SHOULD be given by using properties dcat:startDate or time:hasBeginning, and dcat:endDate or time:hasEnd, respectively. The interval can also be open - i.e., it can have just a start or just an end.
To comply with this, the following revisions are needed:
The min cardinality of dcat:startDate should be set to 0
The fact that dcterms:PeriodOfTime must have at least a start or end date can be specified by using a sh:or constraint on these two properties
Currently, the cardinality of these properties is defined as follows:
1 to 1, for
dcat:startDate:https://github.com/europarl/dcat-ep/blob/2f920e96f60a3c0fcc3207f2c5eec472dcb90cc4/0.3/dcat-ep.shacl.ttl#L1499-L1509
0 to 1, for
dcat:endDate:https://github.com/europarl/dcat-ep/blob/2f920e96f60a3c0fcc3207f2c5eec472dcb90cc4/0.3/dcat-ep.shacl.ttl#L1511-L1520
This implies that a time interval can be open-ended - i.e., a time interval can have only the start date.
However, the usage note of
dcterms:PeriodOfTimein DCAT allows also for time intervals having only the end date - quoting from §6.15 Class: Period of Time:To comply with this, the following revisions are needed:
dcat:startDateshould be set to 0dcterms:PeriodOfTimemust have at least a start or end date can be specified by using ash:orconstraint on these two properties