IslamicLeapYearPattern Enumeration

[This is preliminary documentation and is subject to change.]

The pattern of leap years to use when constructing an Islamic calendar.

Declaration Syntax

Visual Basic

Visual C++

public enum IslamicLeapYearPattern

Public Enumeration IslamicLeapYearPattern

public enum class IslamicLeapYearPattern

Members

Member	Description
Base15	A pattern of leap years in 2, 5, 7, 10, 13, 15, 18, 21, 24, 26 and 29. This pattern and Base16 are the most commonly used ones, and only differ in whether the 15th or 16th year is deemed leap.
Base16	A pattern of leap years in 2, 5, 7, 10, 13, 16, 18, 21, 24, 26 and 29. This pattern and Base15 are the most commonly used ones, and only differ in whether the 15th or 16th year is deemed leap.
Indian	A pattern of leap years in 2, 5, 8, 10, 13, 16, 19, 21, 24, 27 and 29.
HabashAlHasib	A pattern of leap years in 2, 5, 8, 11, 13, 16, 19, 21, 24, 27 and 30.

Remarks

The Islamic, or Hijri, calendar is a lunar calendar of 12 months, each of 29 or 30 days. The calendar can be defined in either observational or tabular terms; Noda Time implements a tabular calendar, where a pattern of leap years (in which the last month has an extra day) repeats every 30 years, according to one of the patterns within this enum.

While the patterns themselves are reasonably commonly documented (see e.g. Wikipedia) there is little standardization in terms of naming the patterns. I hope the current names do not cause offence to anyone; suggestions for better names would be welcome.