188.8.131.52.1.20.10 Property: DTSTART
RFC Reference: [RFC2445] section 184.108.40.206
Number of Instances Allowed: 1
Format: Date-Time ([RFC2445] section 4.3.5), Date ([RFC2445] section 4.3.4)
Importing to Calendar objects
If the METHOD property of the VCALENDAR component is not set to 'COUNTER' or if either X-MS-OLK-ORIGINALEND or X-MS-OLK-ORIGINALSTART is not specified, then this property SHOULD<139> be imported as PidLidAppointmentStartWhole ([MS-OXPROPS] section 2.29), and PidLidAppointmentDuration SHOULD<140> be set to the number of minutes between DTSTART and DTEND.
If DTSTART and DTEND are both specified in floating time, and if both occur at midnight of their respective days, then the appointment SHOULD<141> be imported as an all-day appointment: PidLidAppointmentSubType MUST be set to 0x00000001. Note that this logic SHOULD<142> also be triggered by X-MICROSOFT-CDO-ALLDAYEVENT (section 220.127.116.11.1.20.28) and X-MICROSOFT-MSNCALENDAR-ALLDAYEVENT (section 18.104.22.168.1.20.41).
If the DTEND and DURATION properties are not specified in the VEVENT, the value of DTSTART MAY<143> be used to derive the end time based on the format of the DTSTART property based on the following rules.
If the format of the DTSTART property is a Date-Time, the end time is treated as being equal to the value of DTSTART, and is imported as specified in section 22.214.171.124.1.20.8.
If the format of the DTSTART property is a Date, the end time is treated as being equal to the value of DTSTART + 1 day, and is imported as specified in section 126.96.36.199.1.20.8.
Exporting from Calendar objects
If the METHOD property of the VCALENDAR component is set to 'COUNTER', then PidLidAppointmentProposedStartWhole SHOULD<144> be exported as a new DTSTART property. For other values of METHOD, the PidLidAppointmentStartWhole of a Calendar object SHOULD<145> be exported as a DTSTART property.
If this is an all-day appointment, then this property SHOULD<146> be exported in floating time with the Date format.
If this is a recurring non-all-day appointment, then this property MUST be specified as a local time with a TZID parameter.
Non-recurring non-all-day appointments SHOULD<147> be specified as a local time with a TZID parameter.