5.2.2. Uncertainty

Uncertainty is defined as a “plus or minus” value. Example: At such-and-such a time for so long, beginning (or ending) within “x” time units of the specified start (or end) time.

Issue: ICalendar only deals with exact times. Uncertainties can be applied to a start time or end time.

Proposed: Use a DURATION value specified in xCal for in a new Uncertainty x-property with date time values:

<x-StartTimeUncertainty>P3H20M</x-StartTimeUncertainty>

Uncertainty needs to be expressed with a precision of milliseconds.