5.1.5. VAVAILABILITY
DTSTART
andDTEND
if specifiedMUST
be date-time values.DTSTART MAY
appear once and signifies start of the busy period.Only one of
DTEND
orDURATION MAY
appear and signify the end of the busy period.If
DURATION
does appear in aVAVAILABILITY
, thenDTSTART MUST
also appear in the sameVAVAILABILITY
.