{
	"dtstart":{"format":"date-time","type":"string","description":"Event starting time"},
	"summary":{"type":"string"},
	"location":{"type":"string","optional":true},
	"url":{"type":"string","format":"url","optional":true},
	"dtend":{"format":"date-time","type":"string","description":"Event ending time","optional":true},
	"duration":{"format":"date","type":"string","description":"Event duration","optional":true},
	"rdate":{"format":"date-time","type":"string","description":"Recurrence date","optional":true},
	"rrule":{"type":"string","description":"Recurrence rule","optional":true},
	"category":{"type":"string","optional":true},
	"description":{"type":"string","optional":true},
	"geo":{"type":"object","properties":{"$ref":"http://json-schema.org/geo.properties"},"optional":true}
	}