3
11 384 Tues. 12 Sept. 1950 25 385 Thur. 11 Sept. 2064
12 355 Mon. 1 Oct. 1951 26 354 Thur. 1 Oct. 2065
13 355 Sat. 20 Sept. 1952 27 355 Mon. 20 Sept. 2066
14 383 Thur. 10 Sept. 1953 28 383 Sat. 10 Sept. 2067
15 354 Tues. 28 Sept. 1954 29 354 Thur. 27 Sept. 2068
16 355 Sat. 17 Sept. 1955 30 355 Mon. 16 Sept. 2069
17 385 Thur. 6 Sept. 1956 31 383 Sat. 6 Sept. 2070
18 354 Thur. 26 Sept. 1957 32 355 Thur. 24 Sept. 2071
19 383 Mon. 15 Sept. 1958 33 384 Tues. 13 Sept. 2072

_Mahommedan Calendar._--The Mahommedan era, or era of the Hegira, used in
Turkey, Persia, Arabia, &c., is dated from the first day of the month
preceding the flight of Mahomet from Mecca to Medina, _i.e._ Thursday the
15th of July A.D. 622, and it commenced on the day following. The years of
the Hegira are purely lunar, and always consist of twelve lunar months,
commencing with the approximate new moon, without any intercalation to keep
them to the same season with respect to the sun, so that they retrograde
through all the seasons in about 321/2 years. They are also partitioned into
cycles of 30 years, 19 of which are common years of 354 days each, and the
other 11 are intercalary years having an additional day appended to the
last month. The mean length of the year is therefore 354-11/30 days, or 354
days 8 hours 48 min., which divided by 12 gives 29-191/360 days, or 29 days
12 hours 44 min., as the time of a mean lunation, and this differs from the
astronomical mean lunation by only 2.8 seconds. This small error will only
amount to a day in about 2400 years.

To find if a year is intercalary or common, divide it by 30; the quotient
will be the number of completed cycles and the remainder will be the year
of the current cycle; if this last be one of the numbers 2, 5, 7, 10, 13,
16, 18, 21, 24, 26, 29, the year is intercalary and consists of 355 days;
if it be any other number, the year is ordinary.

Or if Y denote the number of the Mahommedan year, and

R = ((11 Y + 14) / 30)_r,

the year is intercalary when R < 11.

[v.04 p.1002] Also the number of intercalary years from the year 1 up to
the year Y inclusive = ((11 Y + 14) / 30)_w; and the same up to the year Y
- 1 = (11 Y + 3 / 30)_w.

To find the day of the week on which any year of the Hegir