There is (or was) an article in TechNet about Exchange 5.5 migration (migration to Exchange 5.5) that has some nice tables that fit all the properties together and what applies to what. I'll try to paste the tables from that article into this post, they may not format very well though.
You more or less have to use a logic tree to examine various properties to get the type of recurrence and then from there interpret the other properties.
The following table describes the properties shared by recurring appointments, events, and tasks.
Property
Values
Description
DayInterval
1 through 999
Number of days between instances. Used only if RecurringType is 64.
DayOfMonthMask
1st day of month = bit 0
31st day of month = bit 30
Bit field indicating which days of the month are valid for recurrence pattern. Used only if RecurringType is 7 or 12.
DayOfWeekMask
Sunday = bit 0
Saturday = bit 6
Bit field indicating which days of the week are valid for recurrence pattern. Used only if RecurringType is 48, 51, or 56.
DayOfWeekStart
0 through 6
Sunday = 0
Start of week preference. Used only if RecurringType is 48. For recalculating biweekly meetings.
EndRecurringDate
mm-dd-yyyy
End date for recurrence pattern.
EndRecurringTime (Required)
hh:mm
End time for a recurring item.
Exceptions
See "Exceptions Property" section later in this chapter.
Exceptions to a recurring item.
FirstRecurringAlarmDate
Today's date in mm-dd-yyyy format.
First recurring item with alarm. Recalculated during import into Microsoft Outlook.
MonthInterval
1 through 99
Interval between months for recurrence pattern. Used only if RecurringType is 12 or 56.
MonthOfYearMask
January = bit 0
December = bit 11
Bit field indicating which months of year are valid for recurrence pattern. Used only if RecurringType is 7 or 51.
RecurringType (Required)
7 = Yearly on specific day
12 = Monthly on specific day
48 = Weekly
51 = Yearly on a pattern
56 = Monthly on a pattern
64 = Daily
Type of recurrence pattern.
StartRecurringDate (Required)
mm-dd-yyyy
Start date for recurrence pattern.
StartRecurringTime (Required)
hh:mm
Start time for recurring item.
WeekInterval
Positive integer
Interval between weeks for recurrence pattern. Used only if RecurringType is 48, 51, or 56.
YearInterval
Positive integer
Interval between years for recurrence pattern. Used only if RecurringType is 7.
The following table describes additional values required for the RecurringType property.
RecurringType
Required values
7 = Yearly on specific day
DayOfMonthMask, MonthOfYearMask, YearInterval
12 = Monthly on specific day
DayOfMonthMask, MonthInterval
48 = Weekly
DayOfWeekMask, DayOfWeekStart, WeekInterval
51 = Yearly on a pattern
DayOfWeekMask, MonthOfYearMask, WeekInterval
56 = Monthly on a pattern
DayOfWeekMask, MonthInterval, WeekInterval
64 = Daily
DayInterval
Exceptions Property Exceptions are deleted or modified properties of a recurring appointment or task. To delete, only two properties are required: Deleted and InstanceDate. To modify, the appointment or task must be redefined as a single appointment or task, and you must redefine the StartDate and EndDate, even if only the Location property is modified.
Property
Values
Description
Deleted
T or F
If instance was marked "deleted." If FALSE, instance has been modified.
InstanceDate
mm-dd-yyyy
Date that original instance would have occurred.