13.2.1. start
Default
The default value is left up to the server. It may be the current day, start of the current month, etc.
Description
Specifies the start date for the Freebusy data. The server is free to ignore this value and return data in any time range. The client must check the data for the returned time range.
Format
A profile of an IETF RFC 3339 Date/Time. Fractional time is not supported. The server
MUST
support the expanded version e.g.2007-01-02T13:00:00-08:00
It is up to the server to interpret local date/times.
2007-02-03T15:30:00-0800
2007-12-01T10:15:00Z
Date-only values are disallowed as the server cannot determine the correct start of the day. Only UTC or date/time with offset values are permitted.