2.1.4 [RFC5545] Section 3.6.1, VEVENT with No End Time Does Not Take Up Any Time

  • Article

The specification states, "For cases where a 'VEVENT' calendar component specifies a 'DTSTART' property with a DATE value type but no 'DTEND' nor 'DURATION' property, the event's duration is taken to be one day. For cases where a 'VEVENT' calendar component specifies a 'DTSTART' property with a DATE-TIME value type but no 'DTEND' property, the event ends on the same calendar date and time of day specified by the 'DTSTART' property."

Outlook imports VEVENT calendar components that are missing both the DURATION and DTEND properties as ending one hour after their start time. For more details, see section 2.2.70.