2.1.3.1.1.19.2.2 Property: RRULE

RFC Reference: [RFC2445] section 4.8.5.4

Number of Instances Allowed: 0,1

Format: Recurrence rule ([RFC2445] section 4.3.10)

Brief Description: A rule describing the onset of Standard time for years following DTSTART.

Importing to Calendar objects

If this VTIMEZONE component has no DAYLIGHT sub-component, all the bytes in the stStandardDate field of the PidLidTimeZoneStruct structure MUST be set to 0x00 (as specified in 2.1.3.1.1.19.2.1). The remainder of this subsection only pertains to the case where the VTIMEZONE being imported contains one or more DAYLIGHT sub-components.

For basic information regarding the Recurrence rule format, see [RFC2445] section 4.3.10 and section 2.1.3.2.1 of this document.

Time zone recurrences MUST be of frequency YEARLY and MUST specify either a BYDAY or a BYMONTHDAY, but not both.

If a BYDAY is specified, it MUST specify a single occurrence of a single day of the week (e.g. BYDAY=2MO, but not BYDAY=MO or BYDAY=1MO,3MO). The recurrence is imported into the stStandardDate field of the PidLidTimeZoneStruct structure using the following table.

Field of PidLidTimeZoneStruct.stStandardDate

Value

wYear

Set to 0x0000

wMonth

The value of the BYMONTH recurrence part, or, if not present, the month portion of DTSTART property.

wDayOfWeek

The day of the week specified by the BYDAY recurrence part. See section 2.1.3.1.1.19.2.1 and section 2.1.3.2.1.6.

wDay

The occurrence of the day of the week specified by the BYDAY recurrence part. See section 2.1.3.1.1.19.2.1 and section 2.1.3.2.1.6.

If a BYMONTHDAY is specified, it MUST specify a single day of the month (BYMONTHDAY=12, but not BYMONTHDAY=14,15). The recurrence SHOULD<58> be imported into the stStandardDate field of the PidLidTimeZoneStruct structure as specified in the following table.

Field of PidLidTimeZoneStruct.stStandardDate

Value

wYear

Set to 0x0001

wMonth

The value of the BYMONTH recurrence part, or, if not present, the month portion of DTSTART property.

wDayOfWeek

Set to 0x0000.

wDay

The value of the BYMONTHDAY recurrence part.

Exporting from Calendar objects

For basic information regarding the Recurrence rule format, see [RFC2445] section 4.3.10 and section 2.1.3.2.1 of this document.

If the time zone does not observe Daylight Saving Time (DST), this property MUST be omitted.

If the time zone transitions between Daylight Saving Time and Standard Time based on an occurrence of a day of the week, this property MUST be of the form FREQ=YEARLY;BYDAY=byday;BYMONTH=bymonth.

If the time zone transitions between Daylight Saving Time and Standard Time based on a specific day of the month, this property SHOULD<59> be of the form FREQ=YEARLY;BYMONTHDAY=bymonthday;BYMONTH=bymonth.