icalendar - 周期 RDATE 是什么意思？

Question

RFC 5545 允许 RDATE 属性具有 PE​​RIOD 数据类型。该数据类型的语义是什么？据我所知，这是未指定的。它会改变事件的持续时间吗？如果时区更改且没有持续时间怎么办？

Answer 1

尽管我同意您的观点，即 RFC5545 留下了太多需要解释的内容，但在这种情况下，它似乎为 PERIOD 和 RDATE 的组合提供了一些指导:

For example, recurrence instances of a nominal duration of one day will have an exact duration of more or less than 24 hours on a day where a time zone shift occurs. The duration of a specific recurrence may be modified in an exception component or simply by using an "RDATE" property of PERIOD value type.

和

When the combination of the "RRULE" and "RDATE" properties in a recurring component produces multiple instances having the same start DATE-TIME value, they should be collapsed to, and considered as, a single instance. If the "RDATE" property is specified as a PERIOD value the duration of the recurrence instance will be the one specified by the "RDATE" property, and not the duration of the recurrence instance defined by the "DTSTART" property.

示例可用:

RDATE;VALUE=PERIOD:19960403T020000Z/19960403T040000Z,
    19960404T010000Z/PT3H