2.2.1.44.1 RecurrencePattern Structure

The RecurrencePattern structure specifies a recurrence pattern. The fields of this structure are stored in little-endian byte order.

ReaderVersion (2 bytes):  This field MUST be set to 0x3004.

WriterVersion (2 bytes):  This field MUST be set to 0x3004.

RecurFrequency (2 bytes):  An integer that specifies the frequency of the recurring series. Valid values are listed in the following table.

RecurFrequency	Value
Daily	0x200A
Weekly	0x200B
Monthly	0x200C
Yearly	0x200D

PatternType (2 bytes): An integer that specifies the type of recurrence pattern. The valid recurrence pattern types are listed in the following table.

Name	Value	Meaning
Day	0x0000	The event has a daily recurrence.
Week	0x0001	The event has a weekly recurrence.
Month	0x0002	The event has a monthly recurrence.
MonthEnd	0x0004	The event has a month-end recurrence.<12>
MonthNth	0x0003	The event has an every nth month pattern.
HjMonth	0x000A	The event has a monthly recurrence in the Hijri calendar. For this value in the PatternType field, the value of the CalendarType field SHOULD be set to 0x0000.<13>
HjMonthNth	0x000B	The event has an every nth month pattern in the Hijri calendar. For this value in the PatternType field, the value of the CalendarType field MUST be set to 0x0000.
HjMonthEnd	0x000C	The event has a month end recurrence in the Hijri calendar. For this value in the PatternType field, the value of the CalendarType field MUST be set to 0x0000.

CalendarType (2 bytes): An integer that specifies the type of calendar that is used. The acceptable values for the calendar type are listed in the following table.

Name	Value	Meaning
Default	0x0000	The default value for the calendar type is Gregorian. If the value of the PatternType field is HjMonth, HjMonthNth, or HjMonthEnd and the value of the CalendarType field is Default, this recurrence uses the Hijri calendar.
CAL_GREGORIAN	0x0001	Gregorian (localized) calendar
CAL_GREGORIAN_US	0x0002	Gregorian (U.S.) calendar
CAL_JAPAN	0x0003	Japanese Emperor era calendar
CAL_TAIWAN	0x0004	Taiwan calendar
CAL_KOREA	0x0005	Korean Tangun era calendar
CAL_HIJRI	0x0006	Hijri (Arabic Lunar) calendar
CAL_THAI	0x0007	Thai calendar
CAL_HEBREW	0x0008	Hebrew lunar calendar
CAL_GREGORIAN_ME_FRENCH	0x0009	Gregorian Middle East French calendar
CAL_GREGORIAN_ARABIC	0x000A	Gregorian Arabic calendar
CAL_GREGORIAN_XLIT_ENGLISH	0x000B	Gregorian transliterated English calendar
CAL_GREGORIAN_XLIT_FRENCH	0x000C	Gregorian transliterated French calendar
CAL_LUNAR_JAPANESE	0x000E	Japanese lunar calendar
CAL_CHINESE_LUNAR	0x000F	Chinese lunar calendar
CAL_SAKA	0x0010	Saka era calendar
CAL_LUNAR_ETO_CHN	0x0011	Lunar ETO Chinese calendar
CAL_LUNAR_ETO_KOR	0x0012	Lunar ETO Korean calendar
CAL_LUNAR_ROKUYOU	0x0013	Lunar Rokuyou calendar
CAL_LUNAR_KOREAN	0x0014	Korean lunar calendar
CAL_UMALQURA	0x0017	Um Al Qura calendar

FirstDateTime (4 bytes):  An integer that specifies the first ever day, week, or month of a recurring series, dating back to a reference date, which is January 1, 1601, for a Gregorian calendar. The value and its meaning depend on the value of the RecurFrequency field. The value of the FirstDateTime field is used to determine the valid dates of a recurring series, as specified in section 2.2.1.44.1.2.

The value and meaning of the FirstDateTime field for each type of recurrence frequency are specified in the following table. For details about how the value is calculated, see section 2.2.1.44.1.1.

Frequency	Value and Meaning
Daily	The number of minutes between midnight January 1, 1601, and the first ever day on which the event would occur.
Weekly	The number of minutes between midnight January 1, 1601, and the first day of the first ever week in which the event would occur.
Monthly or Yearly	The number of minutes between midnight January 1, 1601, and the first day of the first ever month in which the event would occur.

Period (4 bytes): An integer that specifies the interval at which the meeting pattern specified in PatternTypeSpecific field repeats. The Period value MUST be between 1 and the maximum recurrence interval, which is 999 days for daily recurrences, 99 weeks for weekly recurrences, and 99 months for monthly recurrences. The following table lists the values for this field based on the recurrence frequency, which is specified in the RecurFrequency field.

Frequency	Value
Daily recurrence	The period is stored as the minutes in whole number of days. For example, to define a recurrence that occurs every two days, the Period field is set to 0x00000B40, which equals 2880 minutes, or two days.
Weekly recurrence	The period is stored in weeks. For example, if the Period field is set to 0x00000002, the meeting occurs every two weeks.
Monthly or yearly recurrence	The period is stored in months. If the recurrence is a yearly recurrence, The Period field MUST be set to 12.

SlidingFlag (4 bytes):  This field is only used for scheduling tasks; otherwise the value MUST be zero (0). For more details about sliding tasks, see [MS-OXOTASK] section 3.1.4.6.2.

PatternTypeSpecific (variable):  A structure that specifies the details of the recurrence pattern. The structure varies according to the value of the PatternType field, as specified in sections 2.2.1.44.1.3, 2.2.1.44.1.4, 2.2.1.44.1.5, and 2.2.1.44.1.6.

EndType (4 bytes):  An integer that specifies the ending type for the recurrence. This field MUST be set to one of the values listed in the following table.

Recurrence range type	Value
End after date	0x00002021
End after N occurrences	0x00002022
Never end	SHOULD be 0x00002023 but can be 0xFFFFFFFF

OccurrenceCount (4 bytes):  An integer that specifies the number of occurrences in a recurrence.

When the EndType of the pattern is "End after date", this value has to be computed. Although the value of this field is set, its value has no meaning on a recurring series that has no end date. This value can be set to 0x0000000A for a recurring series with no end date.<14>

FirstDOW (4 bytes): An integer that specifies the day on which the calendar week begins. The default value is Sunday (0x00000000). This field MUST be set to one of the values listed in the following table.

Day	Value
Sunday	0x00000000
Monday	0x00000001
Tuesday	0x00000002
Wednesday	0x00000003
Thursday	0x00000004
Friday	0x00000005
Saturday	0x00000006

DeletedInstanceCount (4 bytes): An integer that specifies the number of elements in the DeletedInstanceDates field.

DeletedInstanceDates (variable):  An array of dates, each of which is the original instance date of either a deleted instance or a modified instance for this recurrence. The number of dates contained in this array is specified by the DeletedInstanceCount field. Each date is stored as the number of minutes between midnight, January 1, 1601, and midnight of the specified day, in the time zone specified by the PidLidTimeZoneStruct property (section 2.2.1.39). The dates are ordered from earliest to latest.

The array contains exactly one element for each deleted instance, and every deleted instance is represented. The array also contains an entry for every modified instance. The array SHOULD NOT contain duplicate entries. Deleted instances for which there is no corresponding value in the ModifiedInstanceDates field imply that they have been completely removed from the pattern.

ModifiedInstanceCount (4 bytes):  An integer that specifies the number of elements in the ModifiedInstanceDates field. The value of this field MUST be less than or equal to the value of the DeletedInstanceCount field.

ModifiedInstanceDates (variable):  An array of dates, each of which is the date of a modified instance. The number of dates contained in this array is specified by the ModifiedInstanceCount field. Each date is stored as the number of minutes between midnight, January 1, 1601, and midnight of the specified day, in the time zone specified by the PidLidTimeZoneStruct property (section 2.2.1.39). The dates are ordered from earliest to latest.

The array contains exactly one element for each modified instance, and every modified instance is represented. The array SHOULD NOT contain duplicate entries. Every modified instance also has to have an entry in the DeletedInstanceDates field with the original instance date.

StartDate (4 bytes):  An integer that specifies the date of the first occurrence. The value is the number of minutes between midnight, January 1, 1601, and midnight of the date of the first occurrence.

EndDate (4 bytes):  An integer that specifies the ending date for the recurrence. The value is the number of minutes between midnight, January 1, 1601, and midnight of the date of the last occurrence. When the value of the EndType field is 0x00002022 (end after n occurrences), this value is calculated based on the number of occurrences If the recurrence does not have an end date, the value of the EndDate field MUST be set to 0x5AE980DF.