...
Model: The interval of OntoCommons project can be expressed in four different ways (as per “4.4.1 Means of specifying time intervals” in ISO8601). Although the screenshots below shows show the complete KG, in practice, the interval oc-period can have be expressed:
by a start and an end: oc-period have has only oc-start and oc-end.
by a duration and context information: oc-period has only oc-duration-exp-ymd.
by start and duration: oc-period has only oc-start and oc-duration-exp-ymd .
by end and duration: oc-period has only oc-end and oc-duration-exp-ymd.
Note: oc-period is expressed in two different wayways, in years, months and days and in days by oc-duration-exp-ymd and oc-duration-exp-d respectively.
...